Solar cell module and panel, and method

ABSTRACT

A laminated module or panel of solar cells and a laminating method for making same comprise an optically transparent top layer and a thermally conductive rear sheet of melt flowable insulating thermoplastic. Solar cells are encapsulated between the top layer and the rear sheet, and electrical connections are provided between a front surface of one solar cell and the back surface of another solar cell. Light passing through the transparent top layer impinges upon the solar cells. Electrical connections may be provided by melt flowable electrically conductive molecularly flexible thermoplastic adhesive or by metal strips or by both. The laminated module in one embodiment may be molecularly flexible and/or may exhibit a particular flexural modulus.

This Application is a continuation of U.S. patent application Ser. No.13/155,069 entitled “SOLAR CELL INTERCONNECTION, MODULE, PANEL ANDMETHOD” filed Jun. 7, 2011, and of U.S. patent application Ser. No.13/155,090 entitled “SOLAR CELL INTERCONNECTION, MODULE AND PANELMETHOD” filed Jun. 7, 2011, each of which U.S. Patent Applicationsclaims the benefit of U.S. Provisional Application Ser. No. 61/397,222filed Jun. 8, 2010, of U.S. Provisional Application Ser. No. 61/455,209filed Oct. 15, 2010, and of U.S. Provisional Application Ser. No.61/492,138 filed Jun. 1, 2011, and each of the foregoing patentapplications and provisional patent applications is hereby incorporatedherein by reference in its entirety.

The present invention relates to a solar cell module and/or panel and toa method for making a solar cell module and/or panel.

FIG. 1 is an exploded view of a conventional prior art solar cell panel900 and FIG. 1A is an enlarged view of interconnected solar cells 920thereof. Conventional solar cell panels 900 typically comprise a numberof solar cells 920, also known as photo-voltaic cells 920, arrayed on aback sheet 910 and covered by a clear or translucent front sheet 930.Individual solar cells 920 have grids of metalized conductive contacts,e.g., fired patterns of glass-silver conductive ink, on both their frontand rear surfaces to provide metalized contacts that conduct the currentproduced when the solar cell 920 is exposed to light.

The metalized conductive grids of adjacent solar cells 920 areinterconnected by metal interconnects or tabs 925 that are soldered tothe metalized contacts on each solar cell 920 to electrically connect anumber of solar cells 920 in series. Each interconnect tab 925 is formedinto an appropriate shape, e.g., an “S” shape, and one end thereof issoldered to a contact on the top surface of one solar cell 920 and theother end thereof is soldered to a contact on the bottom surface ofanother solar cell 920, e.g., to form a string or module of solderedinterconnected solar cells.

A string or module of solar cells 920 may include any convenient numberof solar cells in series, however, strings of 12, 24, 36 and 48 cells inseries are typical. The number of solar cells connected in series may beselected to provide a desired output voltage. Where a large number ofseries connected solar cells are desired, two or more strings or modulesmay be utilized and these strings or modules may be connected in seriesby soldering after mounting to the back sheet 910 so as to avoidhandling a series string having a large number of solar cells. Ingeneral, soldering to interconnect solar cells 920 may be done beforeand/or after the solar cells are attached to back sheet 910, as may beconvenient.

Strings or modules of solder tab interconnected solar cells are placed,e.g., attached, to the back sheet 910 and are covered by the front sheet930. The space between the front and back sheets 910, 930 may be filledwith an encapsulating material 940 and heat-vacuum laminated in a batchlaminating process, and/or may be surrounded by a frame to provide aseal, e.g., to create a sealed space that may be filled with arelatively inert gas.

Typical conventional solar cells may be about 10×10 cm, 12.5×12.5 cm or15×15 cm in size and are typically operated at a voltage of about0.6-0.7 volts, with the level of current generated being a directfunction of the active area of the solar cell and the intensity of thelight impinging thereon, and being inversely related to temperature.

Back sheet 910 may be a plastic and/or a metal, e.g., aluminum. Frontsheet 930 may be, e.g., a clear tempered glass, and encapsulatingmaterial 940 may be, e.g., an ethylene vinyl acetate (EVA) film which isknown to melt flow and provide long term protection against moisturepenetration and to have resistance to degradation by ultra-violet (UV)light. However, EVA in the presence of moisture and heat can becomeacidic and lead to corrosion. Vacuum lamination of panel 900 istypically done at a temperature of about 140° C. and a pressure of aboutseveral hundred millibar to one bar. Interconnect tabs 925 are typicallyof tinned copper, but may be of silver.

The configuration of a typical conventional solar panel 900 may tend torequire manual processing and batch processing. In particular, solderingof interconnects to solar cells often involves a manual solderingprocess, which can be expensive and can produce non-uniform results. Inaddition, vacuum lamination batch processing is typically employed forlaminating a single panel or only a small number of panels at anelevated temperature and pressure selected to permit the EVA material tocure by polymer cross-linking to develop strength followed by a periodof controlled cooling, e.g., up to 5-30 minutes cycle time per unit orbatch.

As a result, vacuum laminating tends to be a processing step thatconstricts the flow of panels to completion, i.e. the laminating becomesa production bottleneck that severely constricts the number of solarpanels that can be processed on a given piece of laminating equipment,thereby reducing output and increasing unit cost.

Accordingly, Applicant has discovered a need for a solar cellinterconnection, module, and/or panel that avoids long curing timesneeded for cross-linking and is suitable for continuous processing andfor a method or process for making such interconnection, module and/orpanel.

To this end, a laminated module of solar cells may comprise: a top layerof a melt flowed melt flowable optically transparent electricallyinsulating thermoplastic having a first pattern of melt flowableelectrically conductive thermoplastic thereon for making electricalconnection to the front surfaces of solar cells; a plurality of solarcells having front and back surfaces to which electrical connection maybe made, the plurality of solar cells being laminated into the meltflowed top layer with the first patterns of melt flowable electricallyconductive thermoplastic making electrical connection to the frontsurfaces of the plurality of solar cells, a rear sheet of a melt flowedmelt flowable electrically insulating thermoplastic having a secondpattern of melt flowable electrically conductive thermoplastic thereonfor making electrical connection to the back surfaces of the pluralityof solar cells, the melt flowed rear sheet being laminated to the meltflowed top layer and to the back surfaces of the plurality of solarcells therein with the second patterns of melt flowable electricallyconductive thermoplastic making electrical connection to the backsurfaces of the plurality of solar cells; wherein the first and secondpatterns of melt flowable electrically conductive thermoplastic are meltflowed to each other to provide an electrical connection between thefront surface of one of the plurality of solar cells and the backsurface of another of the plurality of solar cells.

In one aspect, a laminated module of solar cells may comprise: a toplayer of a melt flowed melt flowable optically transparent electricallyinsulating thermoplastic having a first pattern of melt flowableelectrically conductive thermoplastic thereon for making electricalconnection to the front surfaces of solar cells; a plurality of solarcells having front and back surfaces to which electrical connection maybe made, the plurality of solar cells being laminated into the meltflowed top layer with the first patterns of melt flowable electricallyconductive thermoplastic making electrical connection to the frontsurfaces of the plurality of solar cells, and the back surfaces of theplurality of solar cells being exposed, wherein the first pattern ofmelt flowable electrically conductive thermoplastic melt flowed toprovide exposed electrical connections to the front surfaces of theplurality of solar cells, and wherein the back surfaces of the pluralityof solar cells are exposed for making electrical connection thereto.

Further, a laminated module of solar cells may comprise: a top layer ofa melt flowed melt flowable optically transparent electricallyinsulating molecularly flexible thermoplastic having at least tenpercent molecular crystallites that melt flow at a temperature in therange between about 80° C. and about 250° C. and having a glasstransition temperature of less than about 0° C.; to bond to the frontsurfaces of solar cells; a rear sheet of a melt flowed melt flowableelectrically insulating molecularly flexible thermoplastic having atleast ten percent molecular crystallites that melt flow at a temperaturein the range between about 80° C. and about 250° C. and having a glasstransition temperature of less than about 0° C.; to bond to the backsurfaces of solar cells; a plurality of solar cells having front andback surfaces to which electrical connection may be made, the pluralityof solar cells being encapsulated by the molecularly flexiblethermoplastic of the melt flowed top layer and of the melt flowed rearsheet; electrically conductive interconnection members providingelectrical connections between the front surfaces of ones of theplurality of solar cells and the back surfaces of others of theplurality of solar cells; wherein the melt flowable molecularly flexiblethermoplastic of the top layer is bonded to the front surfaces of theplurality of solar cells and the melt flowable molecularly flexiblethermoplastic of the rear sheet is bonded to the back surfaces of theplurality of solar cells, wherein the laminated module including the toplayer and the rear sheet exhibits a flexural modulus at about 60° C.that is at least fifty percent of the flexural modulus exhibited atabout 20° C. without cross-linking chemical curing.

In another aspect, a method for making a laminated module of solar cellsmay comprise:

-   -   obtaining a top layer of a melt flowable optically transparent        electrically insulating thermoplastic having a first pattern of        melt flowable electrically conductive thermoplastic thereon for        making electrical connection to the front surface of solar        cells;    -   placing a plurality of solar cells having front and back        surfaces to which electrical connection may be made on the melt        flowable top layer in locations with the first pattern of melt        flowable electrically conductive thermoplastic adjacent the        front surfaces of the plurality of solar cells,    -   obtaining a rear sheet of a melt flowable electrically        insulating thermoplastic having a second pattern of melt        flowable electrically conductive thermoplastic thereon for        making electrical connection to the rear surface of the solar        cells;    -   placing the melt flowable rear sheet adjacent to the melt        flowable top layer and the back surfaces of the plurality of        solar cells in a location with the second pattern of melt        flowable electrically conductive thermoplastic adjacent the back        surfaces of the plurality of solar cells;    -   heat laminating the melt flowable top layer, the plurality of        solar cells and the melt flowable rear sheet to melt flow the        melt flowable top layer and the melt flowable rear sheet        together so that electrical connections are made between the        first pattern of melt flowable electrically conductive        thermoplastic and the front surfaces of the plurality of solar        cells, between the second pattern of melt flowable electrically        conductive thermoplastic and the back surfaces of the plurality        of solar cells, and between the first and second patterns of        pattern of melt flowable electrically conductive thermoplastic.

In another aspect, a method for making a laminated module of solar cellsmay comprise:

-   -   obtaining a top layer of a melt flowable optically transparent        electrically insulating thermoplastic having a first pattern of        melt flowable electrically conductive thermoplastic thereon for        making electrical connection to the front surface of solar        cells;    -   placing a plurality of solar cells having front and back        surfaces to which electrical connection may be made on the melt        flowable top layer in locations with the first pattern of melt        flowable electrically conductive thermoplastic adjacent the        front surfaces of the plurality of solar cells,    -   heat laminating the melt flowable top layer and the plurality of        solar cells to melt flow the melt flowable top layer so that        electrical connections are made between the first pattern of        melt flowable electrically conductive thermoplastic and the        front surfaces of the plurality of solar cells;    -   wherein the plurality of solar cells are embedded into the melt        flowable top layer,    -   wherein the first pattern of melt flowable electrically        conductive thermoplastic provides exposed electrical connections        to the front surfaces of the plurality of solar cells, and    -   wherein the back surfaces of the plurality of solar cells are        exposed for making electrical connection thereto.

In a further aspect, a method for making a laminated module of solarcells may comprise:

-   -   obtaining a top layer of a melt flowable optically transparent        electrically insulating molecularly flexible thermoplastic        having at least ten percent molecular crystallites that melt        flow at a temperature in the range between about 80° C. and        about 250° C. and having a glass transition temperature of less        than about 0° C.; to bond to the front surfaces of solar cells;    -   placing a plurality of solar cells having front and back        surfaces to which electrical connection may be made with the        front surfaces thereof adjacent the melt flowable top layer;    -   providing electrical connections between the front surfaces of        ones of the plurality of solar cells and the back surfaces of        others of the plurality of solar cells;    -   placing adjacent the back surfaces of the plurality of solar        cells and top sheet a rear sheet of a melt flowable electrically        insulating molecularly flexible thermoplastic having at least        ten percent molecular crystallites that melt flow at a        temperature in the range between about 80° C. and about 250° C.        and having a glass transition temperature of less than about 0°        C.; to bond to the back surfaces of solar cells;    -   heat laminating the melt flowable top layer, the plurality of        solar cells and the melt flowable rear sheet to melt flow the        melt flowable top layer and the melt flowable rear sheet        together so that the plurality of solar cells and the electrical        connections there between are encapsulated in the melt flowed        molecularly flexible thermoplastic of at least the top layer;    -   wherein the laminated module including the top layer and the        rear sheet exhibits a flexural modulus at about 60° C. that is        at least fifty percent of the flexural modulus exhibited at        about 20° C. without cross-linking chemical curing.

According to another aspect, a laminated module of solar cells havingfront and back surfaces may comprise: a plurality of solar cells havingfront and back surfaces; a top layer of an optically transparentelectrically insulating material adjacent to and having adhesion to thefront surfaces of solar cells; a thermally conductive rear sheetincluding a melt flowable thermally conductive and electricallyinsulating adhesive material having adhesion to the back surfaces ofsolar cells; a plurality of electrical connections, each being betweenthe front surface of one solar cell and the back surface of anothersolar cell; the top layer, thermally conductive rear sheet and pluralityof solar cells being melt flow laminated with at least the melt flowedthermally conductive thermoplastic adhesive material of the thermallyconductive rear sheet; and the top layer adhering to the front surfacesof the solar cells and the thermally conductive rear sheet adhering tothe back surfaces of the solar cells.

A laminated module of solar cells having front and back surfaces maycomprise: a plurality of solar cells having front and back surfaces; atop layer of an optically transparent electrically insulating materialand having adhesion to the front surfaces of solar cells; a thermallyconductive rear sheet comprising a thermally conductive metal sheet anda melt flowable thermally conductive and electrically insulatingadhesive material layer and having adhesion to the back surfaces ofsolar cells and having a thermal conductivity of at least 0.5 Watt permeter ° K; a plurality of electrical connections, each electricalconnection being between the front surface of one solar cells and theback surface of another solar cell; the top layer, thermally conductiverear sheet and plurality of solar cells being melt flow laminated withat least the thermally conductive adhesive material layer of the rearsheet; and the top layer adhering to the front surfaces of the solarcells and the melt flowed thermally conductive rear sheet adhering tothe back surfaces of the solar cells.

BRIEF DESCRIPTION OF THE DRAWING

The detailed description of the preferred embodiment(s) will be moreeasily and better understood when read in conjunction with the FIGURESof the Drawing which include:

FIG. 1 is an exploded perspective view of a prior art solar cell paneland FIG. 1A is an enlarged view of prior art solder tab interconnectedsolar cells thereof;

FIG. 2 is a plan view of an example embodiment of a solar cellinterconnection, module and panel, and FIG. 2A is an enlargedcross-sectional detail thereof;

FIG. 3 is a plan view of an example embodiment of a front or top sheetfor the example solar cell panel of FIG. 1, FIG. 3A is a side viewthereof, and FIG. 3B is a side cross-sectional view of a portionthereof;

FIG. 4 is a plan view of an example embodiment of a rear sheet for theexample solar cell panel of FIG. 1, FIG. 4A is a side view thereof, andFIG. 4B is a side cross-sectional view thereof;

FIG. 5 includes FIGS. 5A-5E which illustrate various steps in a methodor process for making the example solar cell panel of FIG. 1;

FIG. 6 is a schematic diagram of a process flow chart illustrating anexample embodiment of a method for making an example solar cell panel;

FIG. 7 is a schematic diagram illustrating an example roll laminatingprocess useful with the example solar cell panel;

FIG. 8 includes FIGS. 8A, 8B and 8C each of which is a partially cutaway view of part of an example solar cell panel showing an exampleinterconnection arrangement thereon;

FIG. 9 includes FIGS. 9A-9B which illustrate example steps in theprocess or method for making a solar cell panel employing a tabbed solarcell; and

FIG. 10 is a side sectional view of an example embodiment of an examplesolar cell panel, FIG. 10A is a side cross-sectional view of a portionthereof, and FIG. 10B is a side of a component thereof.

In the Drawing, where an element or feature is shown in more than onedrawing figure, the same alphanumeric designation may be used todesignate such element or feature in each figure, and where a closelyrelated or modified element is shown in a figure, the samealphanumerical designation primed or designated “a” or “b” or the likemay be used to designate the modified element or feature. Similarly,similar elements or features may be designated by like alphanumericdesignations in different figures of the Drawing and with similarnomenclature in the specification. According to common practice, thevarious features of the drawing are not to scale, and the dimensions ofthe various features may be arbitrarily expanded or reduced for clarity,and any value stated in any Figure is given by way of example only.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

The novel solar cell interconnections, solar cell modules and solar cellpanels descried herein, and the novel method for making suchinterconnections, modules and panels, involve combinations of structureand configuration, and of materials and properties, that provide certaincharacteristics and advantages over the example prior art solar paneldescribed in relation to FIG. 1.

It is noted that the novel solar cell interconnections, modules andpanels described herein not only overcome certain disadvantages of theprior art panels, but also may be designed to employ certain aspects ofconventional solar panels, e.g., standard size solar cells andprocessing at about 140° C., so as to be conveniently adoptable.

FIG. 2 is a plan view of an example embodiment of a solar cellinterconnection, module and panel 100, and FIG. 2A is an enlargedcross-sectional detail thereof. Solar panel 100 comprises a relativelythin thermoplastic top layer or sheet 200 and an opposing relativelythin thermoplastic rear sheet 300, having a plurality of solar cells 400there between. Both top sheet 200 and rear sheet 300 preferably includeelectrical conductors thereon for cooperatively providinginterconnections between solar cells 400. Example panel 100 has, e.g.,36 solar cells 400 arranged in four rows of nine solar cells 400, andthe 36 solar cells are all electrically connected in series, although agreater or lesser number of solar cells per row or a greater or lessernumber of rows, or both, may be employed, thereby to provide any desirednumber of solar cells per panel 100. Connections to the respective endsof the series connected solar cells 400 may be made at terminals 230 and330.

Solar cells may be, but need not be, typical conventional solar cellsthat may be about 10×10 cm, 12.5×12.5 cm or 15×15 cm in size and aretypically operated at a voltage of about 0.6-0.7 volts, with the levelof current generated being a direct function of the active area of thesolar cell and the intensity of the light impinging thereon, and beinginversely related to temperature. Typically, each solar cell has anelectrically conductive metal grid pattern on the front surface thereoffor conducting charge generated by the solar cell to utilizationcircuitry. In one common solar cell, the conductive grid includes pluralthin narrow parallel metal conductors 412 arranged in one direction andone or more parallel thin metal conductors or bus bars 410 arranged inan orthogonal direction that collect the charge from the thin conductors412 and to which external electrical connection may be made. One or moremetal conductors are also provided on the rear surface of the solar cellfor making electrical contact therewith. The metal conductors may bymade of a fired or sintered glass or ceramic based conductive ink havingconductive metal particles, e.g., gold, silver or copper particles,embedded therein. If the conductors are not solderable, a plating ofsolderable metal may be applied. Solar cells of other configurations andof any desired photo-voltaic material may be employed with theinterconnections, modules and panels 100 described herein.

Conductors 210 associated with top sheet 200 and conductors 310associated with rear sheet 300 cooperate to connect together to provideelectrically conductive connections between bus bar contacts 410 on thefront surface of each solar cell 400 and a contact on the rear surfaceof an adjacent solar cell 400, e.g., in each of the four rows of solarcells 400 of panel 100. Electrical connections between the bus barcontacts 410 of solar cells 400 at the ends of each of the four rowsthereof are made by end cross connections 220 and 320 which areassociated with top layer 200 and rear sheet 300, respectively, andwhich cooperate to electrically connect together.

Top layer 200 includes a relatively thin layer of a relativelytransparent electrically insulating melt flowable thermoplasticpolymeric adhesive into which solar cells 400 are pressed in a heatedlaminating process step described herein, whereby solar cells 400 areencapsulated in top layer 200 and rear sheet 300 which melt flow andbond to the surfaces of solar cells 400 when laminated. Electricalconductors 210, 310 include a patterned melt flowable electricallyconductive thermoplastic polymeric adhesive deposited in a pattern ontop layer 200 and rear sheet 300, respectively, that physically cometogether in the gaps or spaces between adjacent solar cells 400 whenpanel 100 is heat laminated so as to provide an electrical connectionbetween bus bar contacts 410 on the front surface of each solar cell 400and the rear contact of an adjacent solar cell 400.

Similarly, electrical conductors 230, 330 include a patterned meltflowable electrically conductive thermoplastic polymeric adhesivedeposited in a pattern on top layer 200 and rear sheet 300,respectively, that physically come together in the end region betweenadjacent rows of solar cells 400 when panel 100 is heat laminated so asto provide an electrical connection between bus bar contacts 410 on thefront surface of a solar cell 400 at the end of one row of solar cellsand the rear contact of a solar cell 400 of an adjacent row of solarcells 400. Conductors 230, 330 that are at the opposite ends of theseries connections of solar cells 400 provided by conductors 220, 320are arranged to provide respective end contacts 230, 330 to whichelectrical connections may be made, e.g., by electrical wires, forconnecting panel 100 in a utilization configuration wherein electricalpower generated thereby in response to light impinging on panel 100 maybe utilized, e.g., by an electrical load.

Top layer 200 may also include a pattern 250 of melt flowableelectrically insulating thermoplastic adhesive positioned at one or moreof the edges of solar cells 400 so as to insulate the edges of solarcells 400 with respect to conductive adhesive pattern 210, e.g.,typically to insulate the edges of solar cells 400 from any ofconductive adhesive 210 that might melt flow to contact an edge of asolar cell 400 when the melt flowable materials of top layer 200 andconductors 210 are melt flowed together. Preferably, a pattern 250 ofmelt flowable insulating adhesive is provided at least at the edges ofsolar cells 400 at which conductors 210 may come within close proximity.In the example illustrated, a pattern of insulating thermoplasticadhesive 250 is provided at the edge of solar cell 400 at whichconductor 210 will deform to make connection to conductor 310 of rearsheet 300 and at the edge of solar cell 400 opposite that edge.

Processing to melt flow top layer 200, the electrically conductiveadhesive thermoplastics forming conductors 210, 220, 310, 320, and theinsulating adhesive thermoplastic forming insulator 250, e.g., for heatlaminating sheet 200 and 300 and the solar cells 400 and conductorstherebetween, is preferably performed at a melt flow temperature in therange of about 80° C.-200° C. and more preferably at a melt flowtemperature in the range of about 100° C.-160° C. In general, andpreferably, the melt flow adhesives forming sheet 200 and patterns 210,220, 250, 310, 320 all melt flow at about the same temperature, however,the thermoplastic adhesives of patterns 210, 220, 310, 320 may have aslightly lower melt flow temperature than do top layer 200 and rearsheet 300. Heat laminating is preferably performed as a substantiallycontinuous heated rolling process, as described below, but may be byheated vacuum laminating or heated pressing, e.g., which typicallyinvolves batch processing.

The preferred thermoplastic materials employed in top layer 200, rearsheet 300 and in patterned adhesive patterns 210, 220, 230, 250, 310,320, 330 preferably have the property of being “intrinsically” or“molecularly flexible.” By employing intrinsically or molecularlyflexible materials to adhere to and encapsulate solar cells 400, thebuild up of stress due to thermal expansion and contraction is reducedand reliable solar cell modules 200 and panels 100 may be inexpensivelymade.

An intrinsically flexible or molecularly flexible material is a materialthat is flexible as a result of its molecular structure, and not justbecause it has been formed into a very thin sheet. Steel, aluminum andglass can be flexed if made thin enough, but none is intrinsicallyflexible. As used herein, flexible means a material that has a modulusof elasticity that is less than about 35,000 kg/cm² (500,000 psi) andthat withstands an elongation of at least 30% in length without failure.Preferred materials typically have a modulus of elasticity that is lessthan about 3,500 kg/cm² (50,000 psi). Thus, conventional substratematerials, such as polyimide which has a modulus of elasticity of about140,000 kg/cm² (about 2,000,000 psi), is not flexible as that term isused herein. Typically, molecularly flexible thermoplastic polymers havea glass transition temperature Tg that is less than or equal to about 0°C., and preferably is less than about −20° C.

Typical molecularly flexible thermoplastic polymers have a molecularlyflexible backbone with small crystallites attached thereto, such asunmodified PVF or PVDF which have melting points of about 160-165° C.Modification thereof that increases fluorination tends to increaseflexibility and to lower the melting point, e.g., as in the case ofKYNAR® fluoro-polymers available from Arkema, Inc. of King of Prussia,Pa., and certain type ST and type TP adhesives available from AITechnology, Inc. of Princeton Junction, N.J.

Preferred thermoplastic materials typically exhibit a mechanicalstrength and rigidity having a flexural modulus of at least about 10,000psi (about 700 kg/cm²) at ambient temperature, e.g., at about 20° C.,and retain at least about fifty percent (50%) of that strength andrigidity at a temperature of about 60° C. When such thermoplasticmaterials are raised to their melt flow temperature or above, e.g., whenbeing heat laminated, they melt and flow easily after which they mayquickly cool, e.g., to about 60° C. or lower, at which temperature theyexhibit substantial strength and may be removed from the laminatingequipment. As a result, solar cell panels 100 and/or solar cell modules200 may be heat laminated, cooled and handled thereafter in a muchshorter time, e.g., about 2-5 minutes, instead of the 15-30 minutesrequired for vacuum laminating conventional solar panels that employ theconventional materials typically employed therein.

FIG. 3 is a plan view of an example embodiment of a front sheet or topsheet 200 for the example solar cell panel 100 of FIG. 1, e.g., viewedthrough transparent top sheet 200, FIG. 3A is a side view thereof, andFIG. 3B is a side cross-sectional view of a portion thereof. Top layer200 comprises a relatively thin sheet of relatively opticallytransparent melt flowable adhesive thermoplastic through which light maypass to impinge on solar cells 400 which are placed adjacent thereto,e.g., when top layer 200 is heat laminated in a panel 100. Top layer 200comprises a directly bondable electrical circuit structure forproviding, in cooperation with rear sheet 300, heat bondable electricalconnections between the solar cells 400.

On one of the generally parallel broad surfaces of top sheet 200 is apattern of electrical conductors 210 that are sized and arranged tocorrespond to electrical contacts on the front surface of a solar cell400 to be placed adjacent to top sheet 200. Where solar cells 400 have,e.g., two parallel bus bar contacts 410, conductors 210 include twoparallel conductors having a width generally corresponding to the widthof bus bars 410 and having a length that is sufficient to extend beyondthe edge of solar cell 400 to present in the space between adjacentsolar cells 400 placed on top sheet 200. Conductors 210 may be, but neednot be, longer than bus bars 410, however, each conductor 210 extendsbeyond the edge of a solar cell 400.

Preferably, top sheet 200 has one or more targets 244 or other fiducialmarks 244 thereon to provide reference points relative to patterns 210,220, 250 both when applying patterns 210, 220, 250 and when positioningsolar cells 400 on top sheet 200.

Patterned conductors 210 that are at the end of a row, and so will notbe at a space between adjacent solar cells 400 in a row, may have atransverse conductor 220 for making, in cooperation with a conductor 320of rear sheet 300 as described, a connection to the solar cell 400 atthe same end of an adjacent row of solar cells 400. Thus the serieselectrical connection of solar cells 400 runs down one row and up anadjacent row, e.g., in opposite directions in adjacent rows. With aneven number of rows of solar cells 400, both ends of the series stringwill naturally be at the same end of top layer 200; where there are anodd number of rows of solar cells 400, an additional conductor runningthe length of layer 200 or sheet 30 may be needed to make connections toboth ends of the series string at or near the same end of solar cellpanel 100.

The patterned conductor 210 that is at the end of the series connectionof solar cells to which an external connection is desired to be madeprovides an end contact 230 to which an external conductor 240, e.g., anelectrical wire 240, may be connected, e.g., as by soldering or by anelectrically conductive adhesive, e.g., the same adhesive employed forconductors 210, 220. So as to be solderable, end contact 230 may coatedor plated with a solderable metal, e.g., coated or plated or otherwisepassivated with, e.g., silver or a tin plated copper.

Typically, solar cells 400 have one or more elongated “bus bar” contacts410 along their front surface and electrically conductive adhesivepatterns 310 electrically connect to at least ten percent (10%) or moreof the area of contacts 410. Conductive patterns 210, 220, 230 mayinclude a patterned metal conductor, e.g., of copper provided by etchingor by electroless or electrolyte plating, and plated or flashed, e.g.,with tin, silver, nickel, nickel-tin, nickel-silver, gold, or othersolderable oxidation resisting coating. Conductors 210, 210 may beelectrically conductive adhesive or may be a combination of metal andelectrically conductive adhesive. Contact locations 230 typically havethe same construction as patterns 210, but may have a solderable metalcontact surface where patterns 210, 220 do not include metal.

Patterned conductors 210, 220 provide part of an interconnection betweenadjacent solar cells 400, cooperating with corresponding patternedconductors 310, 320 on rear sheet 300 when assembled into a panel 100 tocomplete the interconnections of solar cells 400.

After patterned conductors 210, 220 are formed on top sheet 200, solarcells 400 are placed thereon, e.g., by pick and place manufacturingequipment. Typically the melt flowable adhesive of top layer 200 and theelectrically conductive melt flowable adhesives that form conductors210, 220 are sufficiently tacky to hold solar cells 400 in the positionsat which they are placed, however, the solar cells 400 or the layer 200or both can be preheated, e.g., to about 50° C.-60° C., so as to be moretacky and better hold solar cells 400 in place. Alternatively, a smallarea of pressure sensitive adhesive may be used to hold each solar cell400 in place. Solar cells 400 may be placed on conductors 210, 220 whenthe adhesive thereof is wet or when it has been dried or B-staged.

Patterned conductors 210 may include an optional transverse conductivepart 212 at one end thereof that connects the two parallel conductors210 in a location that will generally be in the gap or space betweenadjacent solar cells placed on top sheet 200, thereby to provide a“π”-shaped (pi-shaped) conductor 210′ and to increase the area ofconductor 210 available for making connections to rear sheet 300 asdescribed.

Top sheet 200 is preferably formed as a relatively thin sheet of arelatively optically transparent melt flowable adhesive thermoplasticthat is resistant to being damaged by exposure to UV radiation, such asa fluorinated polymer, e.g., PVF, PVDF and their copolymers, modifiedcopolymers, and blends thereof. The melt flowable adhesive material oftop sheet 200 typically melt flows at a temperature in the range ofabout 80° C. to about 250° C., and preferably at a temperature in therange of about 100° C. to about 200° C., and more preferably betweenabout 120° C. and about 160° C., which is above the temperature that apanel 100 is expected to experience in service and is below thetemperature at which a solar cell may experience an undesirable changeor be damaged.

The thickness of melt flowed top sheet 200 is greater than the thicknessof solar cell 400, plus the thickness of any interconnecting tabthereon, and in a typical instance, would be about 5 mils (about 0.005inch (i.e. 1 mil=0.001 inch) or about 0.13 mm) thicker than the typical12-16 mils (about 0.30-0.41 mm) thickness of a typical solar cell 400after melt flowing. Typically the thickness of top layer 200 as providedbefore solar cells 400 are placed thereon and before melt flowing is atleast about fifty percent (50%) of the thickness of solar cell 400,where no interconnecting tab is employed. (One mil equals 0.001 inch,and one micron equals 0.001 millimeter (mm), and one millimeter equalsabout 39.4 mils).

Typically, the primary top layer 200 includes a thin layer or sheet of amelt flowable electrically insulating thermoplastic material that doesnot need to cross-link to provide strength, e.g., a polyvinylidenefluoride (PVDF), or a polyvinyl fluoride (PVF), or a copolymer thereof.Top layer 200 may be a single sheet or layer, or may be a single ply ofa laminated or layered sheet. Preferred materials are opticallytransparent, have good UV resistance and good solvent resistance, andadhere to solar cells, glass and electrically conductive adhesives. Ineach instance, all of the melt flowable materials should have similarmelt flow temperatures, however, the melt flowable conductive andinsulating adhesives, e.g., of patterns 210, 220, 250, may have aslightly lower melt flow temperature, e.g., about 10-20° C. lower, thandoes the substrate, e.g., top sheet 200, on which they are applied, solong as all of top layer 200, rear sheet 300 and thermoplastic patterns210, 220, 250, 310, 320 flow during the melt flow lamination processing.

Suitable materials for top layer 200 include modified PVF and/or PVDFpolymer and copolymer materials, preferably thermoplastics having aglass transition temperature of less than 0° C., and having more thanabout ten percent (10%) molecular crystallites that flow at melt flowtemperatures in the ranges set forth above. Materials with lower glasstransition temperatures, e.g., less than about −20° C. and about −40°C., are preferred. Examples of suitable materials include, e.g., PVDFpolymer materials such as KYNAR® type 9301, 2500, 2750, and 2800fluoro-polymers which are available from Arkema, Inc. having an officein King of Prussia, Pa., and similar PVF and PVDF copolymers, and blendsthereof. Other suitable materials for transparent top sheet 200, mayinclude a sheet or film 200 of type TP7090, TP7120, TP7130, SG7130,SG7150 or TP7150 thermoplastic insulating adhesive, which are availablefrom AI Technology, Inc. of Princeton Junction, N.J. Preferred top sheetmaterials, e.g., AI Technology types SG7130, SG7133 and SG7150thermoplastic insulating adhesives, include acrylic for improvingtransparency and adhesion, e.g., to glass and solar cells. If a blendedor copolymer material includes cross-linkable polymers, suchcross-linkable polymers must not amount to more than fifty percent (50%)overall volume fraction.

Alternatively, top sheet 200 may further comprise a melt flowablelaminate sheet including an ethylene vinyl acetate (EVA) layer or sheetto provide additional thickness, and the EVA sheet is laminated to theprimary top layer 200 which includes a thin layer or sheet of PVDF, orPVF, or a copolymer thereof, and/or to a thin sheet of glass, e.g., atempered glass, however, any EVA layer employed is not in contact withsolar cells 400 and connections 210, 220, 310, 320 thereto, and need notcompletely cross-link.

In addition, top sheet 200 may be provided with plural wells or cavities202, one for each solar cell 400, wherein each well 202 is slightlylarger in length and width than is solar cell 400 and has a depth thatis substantially the thickness of solar cells 400, so that solar cells400 will fit therein and be properly positioned. The depth of the wellsor cavities 202 may be slightly less than, but typically is not morethan, the thickness of solar cells 400. The wells 202 in top sheet 200may be formed by applying a sheet 204 having the pattern of wellopenings 202 therein on a sheet 206 having a planar surface, or may beformed by applying, e.g., by layering, thermal forming, melt flowingagainst a heated template mold coated with a release material,screening, printing or otherwise depositing, a pattern of material on asheet 200, 204 having planar surfaces, or by any other suitable manner.When top sheet 200 with solar cells 400 in the wells 202 thereof is meltflowed to form top layer 200, the degree to which the melt flowablematerials of top sheet 200 must melt flow is lessened from that wheretop sheet 200 does not have such wells or cavities 202.

With the known and conventional process of encapsulating the solar cellsin forming the solar module in the construction of solar panel, EVA or across-linkable polyolefin is a critical part that provides the interfacebetween the outer protection layer of glass or glass replacement. In thepresent arrangement, a melt-bonding fluorinated polymer encapsulant isemployed to replace conventional cross linking encapsulants that havethe undesirable attribute of having to cross-link for an extended timeunder vacuum forming procedure or post-curing with or without vacuum orpressure. With the present inventive materials and process, heatlamination is complete once the melt-flowing is complete which tends tominimize bubbles and voids within and between the encapsulant layers.Although heat lamination is preferably done without vacuum, conventionalvacuum heat lamination may be employed, but without the need forextended curing dwell time at high temperature. As a result, thecomplete laminating process can be done within seconds or at least lessthan 5 minutes, rather than 15-30 minutes required with the conventionalprocesses for EVA encapsulant.

More importantly, preferred materials such as types SG7130, TP7090,TP7120, and TP7130, melt flowable fluorinated thermoplastics availablefrom AI Technology of Princeton Junction, N.J., utilize molecularcrystallites within the polymer network to provide the mechanicalstability with a glass transition temperature below 0° C., and in mostcases below −40° C., and with a melt-flow melting temperature betweenabout 80-250° C. More preferable are those fluorinated polymers, polymerblends and copolymers that have melting temperature of crystallites ataround 100-200° C., and preferably in the range of about 120-160° C.,which tends to reduce the trapped mechanical stress and reduce the costof manufacturing.

In addition, such polymer encapsulants exhibit reasonable mechanicalstrength once cooled to below their melting temperature to inducecrystallization of the polymer crystallites. Such mechanical structuralstrength is adequate to provide structural integrity when utilized withtypical backside mechanical structure, even with the conventional solarpanel backside structure or additional mechanical structure such as ametal sheet, aluminum honeycomb, corrugated plastics, and the like.Fluorinated polymers with adequate fluorination have been proven towithstand direct UV exposure for extended periods, some for more than 30years. For example, PVDF and its blends with thirty percent (30%)polymethyl methacrylate (PMMA) acrylic plastics have been used as astructural coating for more than 40 years. PVDF polymers and theircopolymers and blends have also proven to exhibit very hightransmissivity in the 200 nm to 1400 nm spectrum, which allows the finalsolar module or panel to attain higher efficiency. Moreover,conventional encapsulants such as EVA and cross-linked polyolefins havebeen shown to be unable to maintaining their light transmissionefficiency after 20-30 years direct exposure to UV light without thefiltering provided by a protective glass sheet.

Top sheet 200 may include a laminate of materials of the typesdescribed. For example, because PVDF copolymers are substantially moreexpensive than is EVA film, top sheet 200 may include a layer of EVA 206and a layer of modified PVDF or other suitably fluorinated polymer 204,e.g., both being melt flowable and having substantially the same meltflow temperature, so as to reduce the cost of top layer 200 withoutaffecting the manufacturing process for solar panel 100 or compromisingperformance. In a typical example of a laminated top sheet 200, themodified PVDF or other suitably fluorinated polymer sheet 204 may beabout 3-6 mils (about 0.07-0.15 mm) thick and the EVA layer 206 may beabout 10-20 mils (0.25-0.5 mm) thick, depending upon the thickness ofsolar cells 400 including the thickness of any tabbing conductorthereon. The EVA sheet 206 may be employed after a PVDF top sheet 200 isheat laminated with solar cells 400 to form top layer 200, e.g., forattaching a glass layer 208 to top layer 200 in a heat laminatingprocess wherein top layer 200 and rear sheet are heat laminated to formsolar cell panel 100, or in a separate heat laminating step.

In addition, a thin glass layer 208 may be included in top sheet 200,e.g., a tempered glass, to provide a measure of UV reduction and anouter surface relatively resistant to abrasion. The glass sheet 208 maybe part of the laminate stack including top sheet 200 that is heatlaminated to form top layer 200 or may be applied after top layer 200 isheat laminated, preferably directly or by using an adhesive, e.g., as byusing a thin sheet 206 of EVA, an about 2-3 mils (about 0.05-0.08 mm)thick sheet of EVA as an adhesive for adhering the thin glass sheet 208to top layer 200; the glass sheet 208 may be laminated, e.g., when thelaminate stack including top layer 200 and rear sheet 300 are heatlaminated.

The present arrangement may employ a single ply of such materials thathave been pre-laminated with the multilayer of optically transparentfront sheet end and with one or more UV resistant back sheets. In thepreferred embodiment, the fluorinated polymer top layer 200 serves asdirect interface with and encapsulation of the solar cells 400 with orwithout other layers. Rear sheet 300 preferably employs the same UVresistant melt flowable fluorinated polymers either as an interface withor as a replacement for the conventional EVA encapsulant. With thepresent interface materials and construction, there is no dwell timeunder vacuum pressure for curing EVA or cross-linkable polyolefins orequivalent materials, and so processing time is substantially reduced.White fluorinated polymers are preferred, because the UV exposure isreduced thereby and transparency is not necessary. Other UV resistantpolymers such as modified polyethylenes and their blends having a meltflow temperature matching that of top layer 200 may also be employed. AITechnology types SG7113, SG7123 and CB7133 melt flowable thermoplasticsmay be employed for such uses.

The arrangement thought to be most preferred employs a fluorinatedthermoplastic polymer top layer 200 without an additional layer such asglass or an EVA/glass combination, thereby to reduce both material andprocess costs. Rear sheet 300 preferably employs the same materialfilled with thermally conductive fillers, including, e.g., any zincoxide, titanium dioxide and other lower cost fillers, or a combinationthereof. Because rear sheet 300 is not directly exposed to solar and UVlight, and need not be transparent, materials such polyolefins or otherpolymers that include melt-flowing polymeric molecular crystalliteshaving melting temperature at least above 80° C., and preferably between80° C. to 200° C., may be employed and be processed with the sameprocess as top layer 200 and rear sheet 300 of the preferred fluorinatedthermoplastic polymers.

Electrically conductive patterns 210 preferably comprise an electricallyconductive melt flowable adhesive thermoplastic that has good electricalconductivity and melt flows at a temperature that is higher than thehighest temperature that a panel 100 employing such adhesive willexperience in service. Such adhesives melt flow to make intimateelectrical connections, e.g., to the conductors 410 of solar cell 400 asif they had been directly formed, dried, and cured on the sinteredconductors 410, as well as to make intimate electrical connections toelectrical contact materials and other electrically conductive materialsand adhesives. In a typical instance, adhesive patterns 210, 220 wouldhave a thickness of less than about 0.5-5 mils (about 0.01-0.13 mm), andin other instances could have a thickness of less than about 8 mils(about 0.20 mm). Several electrically conductive melt flowablethermoplastic adhesives commercially available from AI Technology, Inc.,located in Princeton Junction, N.J., are suitable. For example, AITechnology type TP8090 electrically conductive adhesive melt flowssuitably at about 100° C.-110° C., AI Technology type TP8120electrically conductive adhesive melt flows suitably at about 130°C.-140° C., AI Technology types TP8130 and ST8130 electricallyconductive adhesive melt flow suitably at about 140° C.-150° C., AITechnology type TP8140 electrically conductive adhesive melt flowssuitably at about 150° C.-160° C., and AI Technology types CB8150,TP8150 and ST8150 electrically conductive adhesive melt flow suitably atabout 160° C.-170° C. Melt flowable electrically conductive adhesive isadhesive that is filled with electrically conductive particles, e.g., ofsilver, gold, plated copper, and the like, so as to become electricallyconductive.

Electrically insulating patterns 250 preferably comprise an electricallyinsulating melt flowable thermoplastic adhesive that melt flows at atemperature that is higher than the highest temperature that a panel 100employing such adhesive will experience in service, e.g., between 80°C.-200° C., and preferably between 100° C.-160° C. Such adhesives meltflow so as to conform over the edges of solar cell 400 during theprocess in which conductive adhesive patterns 210 melt flow to makeintimate electrical connections, e.g., to the conductors 410 of solarcell 400. Insulating adhesive patterns 250 thus insulate solar cells 400from undesired contact by conductors 210, 220, 310, 320. Adhesive 250should have good adhesion to solar cells 400, to electrically conductiveadhesives 210, 220, 310, 320, to top layer 200, and to rear sheet 300.In a typical instance, adhesive patterns 250 would have a thickness ofabout 1-10 mils (about 0.03-0.25 mm). Several electrically insulatingmelt flowable adhesives commercially available from AI Technology, Inc.,located in Princeton Junction, N.J., are suitable. For example, AITechnology type TP7090 electrically insulating adhesive melt flowssuitably at about 100° C.-110° C., AI Technology types TP7120, TP7130and ST7130 electrically insulating adhesive melt flow suitably at about130° C.-140° C., and AI Technology types TP7150 and ST7150 electricallyinsulating adhesive melt flows suitably at about 150° C.-160° C.

In addition, and optionally, patterned conductors 210, 220 may includean etched or deposited, e.g., by electroless plating with or withoutadditional electrolytic plating, or printed patterned metal conductorlayer on the surface of top sheet 200, e.g., a metal conductor of copper(e.g., 0.25-2.0 oz. copper) with tin, nickel, silver or nickel-silverflash or plating, a deposited silver conductor or printed silver filledink plated or flashed with a suitable metal to prevent oxidation, e.g.,tin, silver, nickel-tin, gold and/or nickel-silver, or may be theelectrically conductive melt flowable adhesive screened or printed orotherwise deposited in the desired pattern. Where patterned metalconductors 210, 220 are employed, they may be formed by the sameprocesses employed for making electrical printed circuit boards. Withthis option, the electrically conductive adhesive need only connect to aportion of the area of bus bars 410 of solar cells 400, e.g., about tenpercent (10%) thereof, and insulating adhesive may be employed for theremainder of the area of bus bars 410.

Printing and etching of patterned metal conductors may employ the samemethods employed for making electrical printed circuit boards. Patternedadhesives, e.g., adhesives 210, 220, 250, 310, 320, whether electricallyconductive or not and whether thermally conductive or not, may beapplied by any suitable method, e.g., screening, deposition, printing,inkjet printing and the like.

FIG. 4 is a plan view of an example embodiment of a rear sheet 300 forthe example solar cell panel 100 of FIG. 1, FIG. 4A is a side viewthereof, and FIG. 4B is a side cross-sectional view thereof. Rear sheet300 comprises a relatively thin sheet of stable material and preferablymelt flowable material for supporting solar cells 400 which are adjacentthereto, e.g., when rear sheet 300 is heat laminated in a solar cellpanel 100. Rear sheet 300 comprises a directly bondable electricalcircuit structure for providing, in cooperation with top layer 200, heatbondable electrical connections between the solar cells 400.

On one of the generally parallel broad surfaces of rear sheet 300 is apattern of electrical conductors 310 that are sized and arranged toconnect to electrical contacts on the back surface of a solar cell 400which is placed adjacent to rear sheet 300 when sheet 300 is laminatedin a panel 100. The pattern may be made to match all or part of thecontact on the back surface of cells 400. Example conductors 310 mayinclude, e.g., two parallel conductors or another configuration forelectrically connecting to the contact on the back of solar cells 400.Conductors 310 may be longer or shorted than the size of solar cells400, however, each conductor 310 has a length that is sufficient toextend beyond the edge of a solar cell 400 so as to present in the spacebetween adjacent solar cells 400 placed against rear sheet 300.

Patterned conductors 310 that are at the end of a row, and so will notbe at a space between adjacent solar cells 400 in a row, may have atransverse conductor 320 for making, in cooperation with a conductor 220of top layer 200 as described, a connection to the solar cell 400 at thesame end of an adjacent row of solar cells 400. Thus the serieselectrical connection of solar cells 400 runs down one row and up anadjacent row, e.g., in opposite directions in adjacent rows. With aneven number of rows of solar cells 400, both ends of the series stringwill naturally be at the same end of rear sheet 300; where there are anodd number of rows of solar cells 400, an additional conductor runningthe length of layer 200 or sheet 300 may be needed to make connectionsto both ends of the series string at or near the same end of solar cellpanel 100.

The patterned conductor 310 that is at the end of the series connectionof solar cells to which an external connection is desired to be madeprovides an end contact 330 to which an external conductor 340, e.g., anelectrical wire 340, may be connected, e.g., as by soldering or by anelectrically conductive adhesive, e.g., the same adhesive employed forconductors 310, 320. So as to be solderable, end contact 330 may coatedor plated with a solderable metal, e.g., coated or plated or otherwisepassivated with, e.g., tin, nickel-tin, silver, nickel-silver or a tinplated copper.

Patterned conductors 310, 320 provide part of an interconnection betweenadjacent solar cells 400, cooperating with corresponding patternedconductors 210, 220 on top layer 200 when assembled into a panel 100 tocomplete the interconnections of solar cells 400. Preferably, rear sheet300 has one or more targets 344 or other fiducial marks 344 thereon toprovide reference points relative to patterns 310, 320, both whenapplying patterns 310, 320, and also relative to top sheet 200 forplacing and positioning rear sheet 300 in proper alignment andregistration with top layer 200.

Patterned conductors 310 may include an optional transverse conductivepart 312 at one end thereof that connects the two parallel conductors310 in a location that will generally be in the gap or space betweenadjacent solar cells placed on top layer 200, thereby to provide a“π”-shaped (pi-shaped) conductor 310′ and to increase the area ofconductor 310 available for making connections to conductors 210, 212 oftop layer 200 as described.

Rear sheet 300 is preferably formed of a substrate electricallyinsulating material suitable for supporting conductors 310, 320 andpanel 100. Sheet 300 is typically a relatively thin sheet of apolyethylene terthalate (PET), polyethylene napthalate (PEN) and/or PVDFor a copolymer thereof and may have any suitable thickness, e.g., may beas thin as 3-5 mils (about 0.09-0.13 mm), and may be of a greaterthickness, as may be desired for durability and strength in anyparticular instance. The electrically conductive melt flowable adhesivematerial of conductors 310, 320 of rear sheet 300 preferably melt flowat the same temperature as do the melt flowable adhesives of top layer200, e.g., at a temperature in the range of about 80° C. to about 200°C., and more preferably at a temperature in the range of about 100° C.to about 160° C., which is above the temperature that a panel 100 isexpected to experience in service and is below the temperature at whicha solar cell may experience an undesirable change or be damaged.Preferably, the same electrically conductive melt flowable adhesive isutilized for all of conductors 210, 220, 310, 320.

Suitable materials for rear sheet 300 include EVA, PET, PVF and/or PVDFpolymer materials, e.g., PVDF polymer materials such as KYNAR® type9301, 2500, 2750, and 2800 fluoro-polymers which are available fromArkema, Inc. having an office in King of Prussia, Pa., and similar PVFand PVDF copolymers, and laminates thereof either alone or with othermaterials. Preferred materials have good UV resistance and good solventresistance, and for the layer or layers that are adjacent to solar cells400, have good adhesion to solar cells and their metal contacts, glassand electrically conductive adhesives. In each instance, all of the meltflowable materials should have similar melt flow temperatures, however,the melt flowable conductive adhesives, e.g., of patterns 310, 320, mayhave a slightly lower melt flow temperature, e.g., about 10-20° C.lower, than does the substrate, e.g., rear sheet 300, on which they areapplied.

Because solar panels 100 when exposed to intense sunlight in warm or hotclimates may be heated to relatively high temperatures, e.g.,temperatures rising to as high as about 80-110° C., it is desirable toprovide for conduction of heat away from solar cells 400 so as to lessenthe reduction in their efficiency that occurs with increasingtemperature. Rear sheet 300 may be made thermally conductive so as tolessen such temperature rise, and further may be thermally coupled to ametal back sheet having good thermal conductivity. Where sheet 300includes an EVA, PVF or PVDF material, the EVA, PVF or PVDF material andlaminates thereof may be filled or loaded with thermally conductiveparticles so as to be a thermally conductive material. Such particlesmay include alumina, zinc oxide, and other thermally conductiveelectrically insulating particles. Suitable melt flowable thermallyconductive sheets 304 include, e.g., types EVAT7355 and EVAT7358 whichhave thermal conductivities of about 0.5-4.0 Watts per meter degreeKelvin (i.e. Watt/meter ° K or W·m⁻¹·K⁻¹), and types EVAT7359, SG7113and SG7133 which have a thermal conductivity up to about 12-20Watt/meter ° K, all of which are available from AI Technology, Inc. ofPrinceton Junction, N.J. Rear sheets 300 of the foregoing types may beand preferably are adjacent solar cells 400 for encapsulating solarcells 400, and should have a thickness that is at least the thickness ofany connecting tabs that may be on the back sides of solar cells 400.

Such thermally conductive rear sheets 300, 304, when used with a copperor aluminum outer rear backing sheet 308, e.g., an aluminum sheet 308having a thickness of about 2-5 mils (about 0.02-0.12 mm), or thicker,e.g., about 15 mils (about 0.4 mm), and with a frame, can reduce thejunction temperature of the solar cells 400 substantially, e.g., toabout 70° C., depending upon their thickness. Metal sheet 308 may bepart of a honeycomb, perforated laminate or other structural member, asmay be desired for structural strength and/or thermal conductivity.Metal sheet/layer 308 may be patterned and/or coated on its exteriorfacing surface so as to increase the heat transfer therefrom.

Electrically conductive patterns 310, 320 preferably comprise anelectrically conductive melt flowable adhesive that has good electricalconductivity and melt flows at a temperature that is higher than thehighest temperature that a panel 100 employing such adhesive willexperience in service. Patterns 310, 320, 330 are formed on the surfaceof rear sheet 300 against which the back sides of solar cells 400 willbe disposed. Such adhesives, which may be used wet or after being driedor B-staged, melt flow to make intimate electrical connections, e.g., tothe back contact of solar cell 400 as if they had been directly screenedand cured thereon, as well as to make intimate electrical connections toelectrical contact materials and other electrically conductive materialsand adhesives. In a typical instance, adhesive patterns 310, 320 wouldhave a thickness of about 5-8 mils (about 0.13-0.20 mm). Severalelectrically conductive melt flowable adhesives commercially availablefrom AI Technology, Inc., located in Princeton Junction, N.J., aresuitable. For example, AI Technology type TP8090 electrically conductiveadhesive melt flows suitably at about 100° C.-110° C., AI Technologytype TP8120 electrically conductive adhesive melt flows suitably atabout 130° C.-140° C., AI Technology types TP8130 and ST8130electrically conductive adhesive melt flow suitably at about 140°C.-150° C., AI Technology type TP8140 electrically conductive adhesivemelt flows suitably at about 150° C.-160° C., and AI Technology typesTP8150 and ST8150 electrically conductive adhesive melt flow suitably atabout 160° C.-170° C. Melt flowable electrically conductive adhesive isadhesive that is filled with electrically conductive particles, e.g., ofsilver, gold, plated copper, and the like, so as to become electricallyconductive. Because the conductive adhesive 310, 320 is protectedagainst direct UV exposure, suitable conductive adhesives typically havea melt-flow temperature at about the same melt flow temperature as toplayer 200, and may include AI Technology types CB8130 and ESP8450, andthe like.

In addition, and optionally, patterned conductors 310, 320 may includean etched or deposited, e.g., by an electroless plating with or withoutelectrolytic plating, or printed patterned metal conductor layer on thesurface of rear sheet 300, e.g., a metal conductor of copper (e.g.,0.25-2.0 oz. copper) with tin, silver or nickel-silver flash or plating,a deposited silver conductor or printed silver filled ink plated orflashed with a suitable metal to prevent oxidation, e.g., tin, nickel,nickel-tin, silver, gold and/or nickel-silver, or may be theelectrically conductive melt flowable adhesive screened or printed orotherwise deposited in the desired pattern. Where patterned metalconductors 310, 320 are employed, they may be formed by the sameprocesses employed for making electrical printed circuit boards. Withthis option, the electrically conductive adhesive need only connect to aportion of the contact area of solar cells 400, e.g., about ten percent(10%) thereof, and insulating adhesive may be employed for the remainderof the area thereof.

Printing and etching of patterned metal conductors may employ the samemethods employed for making electrical printed circuit boards. Patternedadhesives, e.g., adhesives 210, 220, 250, 310, 320, whether electricallyconductive or not and whether thermally conductive or not, may beapplied by any suitable method, e.g., screening, stenciling, rollcoating, masking, deposition, printing, screen printing, inkjetprinting, sheet laminating, and the like.

While all melt flowable materials of top layer 200, rear sheet 300 andthe patterned adhesives thereon should have similar melt flowtemperatures, it is thought preferable that the melt flow temperaturesof the layer directly facing the incoming sunlight have a slightlyhigher melt flow temperature than the layer or layers behind it. Forexample, if rear sheet 300 is a PVDF layer that melt flows at about 135°C.-150° C., e.g., as does a KYNAR® 2750 PVDF material and suitableblends thereof, then top layer 200 may be a PVDF layer that melt flowsat about 120° C.-130° C., e.g., as does a KYNAR® 2500 PVDF material andsuitable blends thereof, and electrically conductive adhesives such asAI Technology types TP8130, ST8130, TP8140 and ST8150 adhesives modifiedfor such polymers may be employed. While fluorinated thermoplasticpolymers and their blends are preferred, other UV resistant polymersthat melt flow or melt bond at a temperature between about 80-200° C.that is close to the melt flow temperature of top layer 200 may beemployed.

FIG. 5 includes FIGS. 5A-5E which illustrate various steps in a methodor process 500 for making the example solar cell panel 100 of FIG. 1 andFIG. 6 is a schematic diagram of a process flow chart illustrating anexample embodiment of a method 500 for making the example solar cellpanel 100. Therein, only a portion of the solar cells and elements ofpanel 100 are shown. While references such as top layer 200, rear sheet300, the front and back of solar cells 400 and the like may be used indescribing process 500, e.g., for consistency with description of sucharticles, terms such as top, rear, front, back and the like do notnecessarily describe positions or orientations of elements in process500.

Unlike conventional solar cell panel assembly processes which typicallystart with assembling solar cells into strings or modules, followed bymounting the strings or modules with the back side of the solar cells ona back plate, and then encapsulating and covering the back plate and thefront of the solar cells with a transparent front pane, process 500begins with a melt flowable top or front sheet having melt flowableconductors thereon, placing the solar cells on the top sheet with theirfront sides adjacent the top sheet, and placing the rear sheet over thesolar cells. The stack is heat laminated to melt flow the top sheet andthe melt flowable conductors to make interconnections between solarcells and encapsulate the solar cell panel. This process could bereferred to as “reflow molding” of the solar cells 400 into a solarpanel 100.

Advantageously, process 500 avoids the costly and difficult conventionalsteps of soldering solar cells into series strings, of transferring andmounting the series strings of solar cells onto the back plate, and ofbatch processing for vacuum laminating the panels. Also advantageously,process 500 and solar cell panel 100 are compatible with readilyavailable standard solar cells and with certain materials of provenperformance, thereby reducing technical and reliability risk. Inaddition, only a heat laminating process need be employed in assemblingsolar cell panels 100, other processes such as soldering, which for theinterconnection of solar cells can introduce stress and lead topotential failure, are avoided.

In FIG. 5A, step 510 includes obtaining 510 the melt flowableelectrically insulating top sheet 200 as described, which, if the topsheet does not already have the pattern 210, 220 of melt flowableelectrically conductive adhesive thereon, may further include the stepsof applying 514 the pattern of melt flowable electrically conductiveadhesive 210, 220 to one surface of the melt flowable top sheet and ofapplying 516 the pattern of melt flowable electrically insulatingadhesive 250 to the one surface of the melt flowable top sheet. Topsheet 200 is thus ready to receive solar cells 400 thereon.

In FIG. 5B, solar cells 400 are placed 520 on the conductive adhesivepattern with their front (light sensitive) side against the conductiveadhesive pattern 210 and top sheet 200. Placing 520 includes aligningthe solar cells relative to conductive adhesive pattern 210 so that thepart of the conductive adhesive pattern that corresponds to theelectrical contact on the front of the solar cell is adjacent theelectrical contact of the solar cell for making electrical connectionthere between. The part of the conductive adhesive pattern 210 that isto eventually contact the conductive adhesive pattern 310 of the rearsheet 300 is at this step exposed at one edge of the solar cell, e.g.,is not covered by the solar cell, and the opposite edge of the solarcell is partially covering the insulating adhesive 250. Thus, parts ofboth the electrically conductive adhesive 210 and the electricallyinsulating adhesive 250 are exposed at opposite edges of the solar cell400.

Typically, the adhesive material of top sheet 200 is sufficiently tackyso as to retain solar cells 400 pressed against top sheet 200 on topsheet 200, however, either top sheet 200 or solar cells 400 or both maybe heated so as to increase tackiness to the extent desired or necessaryto retain solar cells 400 on top sheet 200, e.g., to about 60° C. Topsheet 200 may have recesses or wells sized for receiving solar cells 400therein. Preferably, top sheet 200 has one or more targets 244 or otherfiducial marks 244 thereon to provide reference points relative toadhesive patterns 210, 220, 250 for use both when applying patterns 210,220, 250 and when positioning solar cells 400 on top sheet 200.

In FIG. 5C, top sheet 200 and solar cells 400 are heat laminated 530 ata temperature and pressure sufficient to melt flow the materials of toplayer 200 and adhesives 210, 220, 250 thereon, so that solar cells 400are pressed into the melt flowed materials and adhesives. As a result,solar cells 400 are embedded in top layer 200 and have conductiveadhesive connections 210 made to the conductive grid contacts 410 ontheir front sides. Insulating adhesive 250 melt flows to conform to theedges of solar cells 400 to insulate these edges from melt flowedconductors 210. Top layer 200 with solar cells 400 embedded thereinpreferably has relatively planar front and rear surfaces and has arelatively uniform thickness, and the back surfaces of solar cells 400and the electrical contacts thereon are exposed, as are contactsprovided by the portions of electrically conductive adhesive 210 thatextend beyond the edges of solar cells 400, for subsequently makingelectrical connection thereto. A relatively stiff backing panel orpanels may be employed when heat laminating top layer 200 for definingthe relatively planar front and/or rear surfaces thereof.

Heat laminated top layer 200 may be utilized as a module of solar cells200 wherein the solar cells 400 are embedded in an optically transparentlayer 200 and wherein connections may be made to both the fronts andbacks of solar cells 400 at a relatively planar surface at the rear ofheat laminated top layer 200. While modules 200 may include all of thesolar cells 400 embedded into the heat laminated top layer 200, that toplayer 200 may be separated into smaller modules having lesser numbers ofsolar cells 400, e.g., as in separating step 570, as may be desired.

Step 530 may include placing 534 a release liner 536 against top layer200 and solar cells 400 prior to heat lamination 530 so that top layer200 does not adhere to the laminating roller or plate, whether or notsuch roller or plate is heated, and removing the release liner 536following the laminating 530. A Teflon® release liner or other suitablerelease liner material may be employed and is preferably slightly largerthan is top layer 200. Preferably, a release liner 536 is utilizedagainst the side of top layer 200 that has the back sides of solar cellsthereon, and a release liner may also be utilized against the other sideof layer 200 as well. In step 560, a relatively stiff backing may beplaced against the exposed side of release liner 536 and/or a glasssheet may be placed against the exposed side of top sheet 200, e.g.,opposite the front sides of solar cells 400.

At this stage following step 530, or following step 544 where adhesivepatterns 310 and/or 320 is applied to top layer 200, top layer 200 issuitable for providing articles including one or more solar cells and/orproviding encapsulated single or plural solar cells 400 for inclusioninto other articles. In this instance, top layer 200 and solar cells 400thereon are heat laminated 530 to melt flow into the top layer structureas shown, however, where a panel 100 is to be made, heat laminating step530 may be omitted and top layer 200, solar cells 40 and rear sheet 300may all be heat laminated 560 in one operation. Thus, heat laminating530 may be optional and one heat lamination 560 may be necessary.

In FIGS. 5D and 5E, step 540 includes obtaining 540 the electricallyinsulating rear sheet 300 as described, which, if the rear sheet 300does not already have the pattern 310, 320 of melt flowable electricallyconductive adhesive thereon, may further include the steps of applying544 the pattern 310, 320 of melt flowable electrically conductiveadhesive to one surface of the rear sheet 300. It is noted thatconductive adhesive patterns 310, 320 may be applied to rear sheet 300before sheet 300 is aligned with and laminated to top layer 200, or maybe applied to top layer 200, e.g., on the side thereof having the backsof solar cells 400 exposed. Rear sheet 300 is thus ready to be assembledto top layer 200 from step 530 and is aligned with and placed against550 top layer 200.

With rear sheet 300 and top layer 200 in proper alignment 550, theportions of conductive patterns 310, 320 that make connection to theback contact of solar cells 400 are adjacent to the back contacts ofsolar cells 400 and the portions of electrically conductive adhesivepatterns 310, 320 that are to make connection to the exposed portions ofelectrically conductive adhesive patterns 210, 220 of top layer 200 areadjacent the exposed portions of electrically conductive adhesivepatterns 210, 220.

Step 560 includes heat laminating 560 rear sheet 300 and top layer 200at a temperature and pressure that will melt flow at least top layer 200and adhesive patterns 210, 220, 250, 310, 320 thereof to adhere to theback contacts of solar cells 400 and to rear sheet 300, which may alsobe of a melt flowable material, to form solar panel 100 as shown.Preferably, heat laminating 560 includes heated rolling lamination 560wherein the heat lamination proceeds essentially in a line (rolls)across a top layer 200 and/or a solar cell panel 100 so that all air orother gas is pressed out ahead of the laminating edge and tends not tobecome trapped or form bubbles or voids, which can lead tode-lamination, as can occur with press or vacuum laminating.

Specifically, in step 560 the exposed portions of electricallyconductive thermoplastic adhesive patterns 210, 310 are adjacent andoverlapping, and melt flow together to complete a permanent electricalconnection between the front contact of each solar cell 400 and the backcontact of the adjacent solar cell 400. Further, in step 560 the exposedportions of electrically conductive thermoplastic adhesive patterns 220,320 are adjacent and overlapping, and melt flow together to complete apermanent electrical connection between the front contact of a solarcell 400 at the end of one row and the back contact of the solar cell400 in the row adjacent thereto. At the same time, thermoplastic toplayer 200 and insulating thermoplastic adhesive patterns 250 melt flowin step 560 to adhere to the portions of rear sheet 300 that do not haveconductive adhesive 210, 220, 310, 320 thereon, thereby to form acontinuous and substantially void-free interface between top layer 200and rear sheet 300 of solar panel 200.

Step 560 may include placing 564 a release liner 566 against rear sheet300 prior to heat lamination 560 so that rear sheet 300 does not adhereto the laminating roller or plate, whether or not such roller or plateis heated, and removing the release liner 566 following the laminating560. A Teflon® release liner or other suitable release liner materialmay be employed and is preferably slightly larger than is solar panel100. Preferably, a release liner 566 is utilized against the rear sheet300, and a release liner may also be utilized against top layer 200 aswell.

Because all of the layers 200, 300 and the adhesives 210, 220, 250, 310,320 adjacent solar cells 400 are thermoplastic and do not requirecomplete cross-linking for strength, the heat laminating step 530, 560need only last for a sufficient time to heat and melt flow thesethermoplastic materials, which time can be quite short, e.g., typicallyabout 1-3 minutes. No extended curing time at elevated temperature isrequired; “curing” is complete when the temperature drops sufficientlybelow the melt flow temperature of the thermoplastic materials. As aresult, many more solar cell panels 100 can be processed in a givenperiod of time than is the case for conventional solar panels whichrequire long cure times, e.g., typically 15-30 minutes, to allow forcomplete cross-linking of polymer materials for strength. This featureof the present arrangement and method produces a significant advantagein the efficient utilization of laminating equipment, e.g., processingup to 20-60 units per hour as contrasted to the 2-4 units per hour withvacuum lamination of conventional solar panels, thereby to reduce unitproduction time and cost.

In addition, because the present structure and method can employ rolllamination 530, 560, as may be preferred, bubbles and voids tend to besqueezed out by the rolling action and so vacuum lamination, and theattendant cost of vacuum lamination equipment, can be avoided. However,the present arrangement and method can employ vacuum lamination in steps530 and/or 560 if desired, or if vacuum lamination equipment isavailable. In this instance, the processing time per unit is stillsubstantially less than for a conventional panel, and so significantimprovement in efficiency and reduction in cost can be expected. Shouldone or more layers in the present arrangement include EVA or anothercross-linking polymer, the laminating steps need not be any longer thanneeded to melt flow the thermoplastic materials, and any cross-linkingneeded can occur in subsequent post-curing without vacuum.

FIG. 7 is a schematic diagram illustrating a roll laminating apparatus600 useful for making solar cell panels 100, e.g., for performing steps530 and/or 560 of method 500. Laminating rollers 610 are spaced apart bya spacing that is substantially the desired thickness of the laminatedproduct, e.g., laminated top layer 200 in step 530 or laminated solarpanel 100 in step 560. Typically, rollers 610 are heated, e.g., to atemperature higher than the desired melt flow temperature, and aredriven to rotate at a rate or rotation suitable for moving top layer 200and/or solar panel 100 through at a speed at which they are raised tothe desired melt flow temperature for heated roll laminating.

Melt-lamination apparatus 600 may employ suitable rubberized pressurerolls which can form laminated encapsulated modules and panels havingminimal voids or with no voids. Encapsulation and the minimizing ofinterfacial voids may further be enhanced by laminating at a highertemperature, e.g., at a temperature above the melting points of thecrystallites of the melt flowable thermoplastic polymer and/or with aslightly greater thickness. Alternatively, a standard batch based vacuumlamination process can also be used. The enhancement of instantmelt-flow and encapsulation of the present arrangement eliminates theneed for the extended dwell time at temperature for chemical curing ofEVA type or other cross-linking encapsulants.

Where a laminating speed is desired that is higher than a speed at whichheated laminating rollers 610 can transfer heat to top layer 200 and/orsolar panel 100 quickly enough to raise it to the desired melt flowtemperature, top layers 200 and/or solar panels 100 to be laminated maypass one or more heating elements 630, e.g., radiant heating elements630 or heated surface 650, so as to be heated substantially to the meltflow temperature prior to entering heated laminating rollers 610 whereinthe melt flowable materials thereof melt flow from being heated to themelt flow temperature and are heat laminated.

A plurality of idler rollers 620 may be provided along a path leadingaway from heated rollers 610 to support the heated laminated top layer200 and/or solar panel 100 after heat lamination while it cools to atemperature below the melt flow temperature of the various melt flowableelements thereof at which it can be removed from being supported, e.g.,by rollers 620. The length and/or width of the path of rollers 620 maybe substantially longer than the length and width of a top layer 200and/or of a solar panel 100 so that plural top layers 200 and/or pluralsolar panels 100 may be moved away from heated rollers 610 and supportedby rollers 620 while they cool, whereby the time needed for a top layer200 and/or a solar panel 100 to cool sufficiently doesn't delay the heatlaminating of subsequent top layers 200 and/or solar panels 100.

Laminated top layers 200 eg whether for use as solar cell modules 200 oras top layers 200 for lamination with a rear sheet 300, and/or laminatedsolar cell panels 100 may be collected in any convenient manner, e.g., acontainer 650 may be provided, for storage, packaging, and/or shipmentthereof. Optionally, container 650 may have a weight responsive basethat when empty is substantially at the level of rollers 620 and thatmoves downward as solar panels 100 are stacked thereon, as may beprovided by one or more supporting springs or by an electrical or othermechanical drive. Optionally, the release liner may be left in place ona laminated top layer 200 and/or a laminated solar panel 200 so as toprotect the surface thereof, e.g., for stacking for storage, packing,and/or shipment, and may be removed prior to use.

Roll lamination of top layers 200 and/or solar panels 100 may employ arelatively stiff or rigid backing sheet, for supporting the top layer200 or panel 100 during roll lamination, thereby to define a plane towhich the melt flowed laminated product will substantially conform.Examples include, e.g., a sheet of metal such as aluminum or thermosetpanels such as epoxy or a laminate that maintains its flatness and shapeat the melt flow temperature employed for lamination of modules 200and/or panels 100, For example, a backing sheet may be employed againstrelease liner 536, e.g., for defining a plane to which the back surfacesof solar cells 400 and melt flowed top sheet 200 including adhesivepatterns 210 thereon conform, e.g., against release liner 536.

Heat laminated top layer 200 may be utilized as a module of solar cells200 embedded in an optically transparent layer 200 wherein connectionsmay be made to both the fronts and backs of solar cells 400 at arelatively planar surface at the rear of heat laminated module 200. Toplayer 200 may be separated into smaller modules having lesser numbers ofsolar cells 400, e.g., as in separating step 570, as may be desired.

Where laminating 560 is to be performed by a continuous heated rolllamination wherein materials to be laminated are supplied from supplyrolls 660, both top layers 200 and rear sheets 300 may be provided fromrolls or strips thereof, and the continuous laminating 560 processingresults in a relatively long sheet or strip of solar panels 100. In thatinstance, the long sheet of solar panels 100 may be cut 570 or otherwiseseparated 570 into individual solar panels 100, e.g., by a verticallymovable blade 640 and an anvil 642, and may then be collected incontainer 670.

Where laminating 560 is to be performed by a heated roll laminationwherein materials to be laminated are supplied as relatively long and/orlarge sheets, e.g., top layers 200 and/or rear sheets 300 may beprovided as large sheets, the continuous laminating 560 processingresults in a relatively long and/or large sheet of laminated top layers200 and/or solar panels 100. In that instance, the long and/or largesheet of top layers 200 and/or solar panels 100 may be cut 570 orotherwise separated 570 into individual solar cell modules and/or solarpanels 100, e.g., by a vertically movable blade 640 and an anvil 642,and may then be collected, e.g., in container 670.

Apparatus 600 may be provided with supply rolls 660 including suppliesof top layer 200 from roll 662 and rear sheet 300 from roll 663 whichcome together as a laminate stack and are fed into heated rollers 610.Supply rolls 660 may also include one or more rolls 664 of release linerthat supply release liners that overlie surfaces of top layer 200 and/orsolar cell panels 100 prior to the heated roll lamination thereof intotop layer 200 and/or solar cell panels 100 and further may be providedwith one or more take up reels 665 that wind the release liner removedfrom top layer 200 and/or solar cell panels 100 following the heatedroll lamination thereof.

FIG. 8 includes FIGS. 8A, 8B and 8C each of which is a partially cutaway view of part of an example solar cell panel 100 showing an exampleinterconnection arrangement 210, 220, 310, 330 thereon. Therein,examples of solar cells 400 having different grid patterns on theirfront (active) surfaces are employed in a solar cell panel 100 accordingto the present arrangement and method.

In FIG. 8A, solar cells 400 have a single elongated bus bar 410 with aplurality of narrow elongated conductors extending perpendicularlythereto in both directions on the front surface thereof. These aretypically sintered metal conductors. Electrically conductive adhesivepatterns 210 have a corresponding single elongated conductorsubstantially overlying bus bar 410. So as to minimize covering(reducing) the active area of solar cell 400, bus bars 410 are typicallymade as small in area as possible and electrically conductive patterns210 preferably are correspondingly minimized to substantially coincidewith bus bars 410. Top layer 200 electrically conductive adhesivepatterns 220 typically are made wider where not adjacent the frontsurfaces of solar cells 400 to as to reduce electrical resistance. Rearsheet 300 electrically conductive adhesive patterns 310, 320 may have anelongated rectangular shape or other desired shape, but typically may bemade wider to as to reduce electrical resistance. Electricallyconductive adhesive patterns 220, 320 may be routed to any desiredlocations, e.g., close together or apart at the narrow end of solarpanel 100 or at one or both longer sides thereof, at which connectionsto external circuitry may be made, e.g., as by wires 240, 340.

In FIG. 8B, solar cells 400 have double elongated bus bars 410 with aplurality of narrow elongated conductors extending perpendicularlythereto in both directions on the front surface thereof. These aretypically sintered metal conductors. Electrically conductive adhesivepatterns 210 have corresponding double elongated conductorssubstantially overlying double bus bars 410. So as to minimize covering(reducing) the active area of solar cell 400, bus bars 410 are typicallymade as small in area as possible and electrically conductive patterns210 preferably are correspondingly minimized to substantially coincidewith bus bars 410. Top layer 200 electrically conductive adhesivepatterns 220 typically are made wider to as to reduce electricalresistance. Rear sheet 300 electrically conductive adhesive patterns310, 320 may have an elongated rectangular shape or other desired shape,e.g., may have single or double conductors, but typically are made widerto as to reduce electrical resistance. Electrically conductive adhesivepatterns 220, 320 may be routed to any desired locations, e.g., closetogether or apart at the narrow end of solar panel 100 or at one or bothlonger sides thereof, at which connections to external circuitry may bemade, e.g., as by wires 240, 340.

In FIG. 8C, solar cells 400 have no bus bar or other sintered metalconductors thereon, but are typically covered in a thin transparentelectrically conductive layer, e.g., a layer in indium-tin oxide. Inthis instance, electrically conductive adhesive patterns 210 may havesingle or double elongated bus bars 210 with a plurality of narrowelongated conductors 214 extending perpendicularly thereto in bothdirections on the front surface thereof, thereby to become melt flowedand electrically connected to the front surface of solar cells 400 whentop layer 200 is heat laminated, thereby to serve the same function asthe bus bars and other thin conductors of the solar cells 400 describedabove. So as to minimize covering (reducing) the active area of solarcell 400, electrically conductive patterns 210 preferably are made assmall in area as possible. As above, top layer 200 electricallyconductive adhesive patterns 220 and rear sheet conductors 310, 320 aretypically made wider to as to reduce electrical resistance. Rear sheet300 electrically conductive adhesive patterns 310, 320 may have anelongated rectangular shape or other desired shape, e.g., may havesingle or double conductors. Also as above, electrically conductiveadhesive patterns 220, 320 may be routed to any desired locations atwhich connections to external circuitry may be made.

Preferably, electrically conductive thermoplastic adhesive patterns 210include a metal electrical conductor. In this instance, a patternedmetal conductor pattern may be formed on a transparent top sheet 200,e.g., a sheet of AI Technology type TP7090, TP7120, TP7130, SG7130,SG7150 or TP7150 thermoplastic insulating adhesive, e.g., by patternetching as in printed circuit boards or by depositing metallizingdirectly on sheet 200, e.g., by electroless or electrolytic plating, orby another suitable process. Preferably the metallization is protectedby a tin, nickel, nickel-tin, nickel-silver or other precious metalfinish, and the pattern 210, 220 of electrically conductivethermoplastic adhesive, e.g., of AI Technology type TP8090, TP8120,TP8150 or ST8150 thermoplastic electrically conductive adhesive may bedeposited thereon. The electrically conductive adhesive is formed inlines of a sufficient width, e.g., about 2 mils (about 0.05 mm) or more,which is at least the width of the fine metallization lines.

FIG. 9 includes FIGS. 9A-9B which illustrate example steps in theprocess or method for making a solar cell panel 100 employing a tabbedsolar cell 400. Tabbed solar cells 400 have one or more elongatedsolderable metal connection tabs 415 soldered to the one or moreconductive bus bars 410 on the front thereof and extending beyond afirst edge thereof, and has one or more solderable elongated metalconnection tabs 425 soldered to the conductive contact or contacts onthe back of solar cell 400 and extending beyond an edge opposite thefirst edge thereof. Metal connection tabs 415, 425 are typically silveror tinned copper so as to be solderable, e.g., for assembly of solarcells 400 into series strings. Thus, metal conductors 415, 425 areavailable outside the edges of tabbed solar cells 400 for makingelectrical connections thereto.

In FIG. 9A, top sheet 200 has melt flowable electrically conductiveadhesive patterns 210, 220 located thereon in positions adjacent towhere connection tabs 415 of solar cells 400 will be located for makingelectrical connection thereto. Top sheet 200 may also include meltflowable electrically insulating adhesive patterns 250 for insulatingthe edges of solar cells 400 as described.

Top sheet 200 may have wells 202 therein for receiving solar cells 400therein, as illustrated, and wells 202 may have features into which tabs415 will reside when solar cells 400 are placed on sheet 200 in whichinstance electrically conductive adhesive patterns 210, 220 on thesurface of top sheet 202 may extend into wells 202 thereof for assuringconnection to tabs 415. Even if wells 202 are not provided, connectiontabs 415 are substantially stiffer than are the melted melt flowablematerials of top sheet 200 and of adhesives 210, 220, 250 thereon sothat the melt flowable materials will flow around tabs 415 and tabs 415will become embedded in top layer 200 and allow connections to be madeto conductors 210, 220 without introducing substantial stress on solarcell 400.

Rear sheet 300 has melt flowable electrically conductive adhesivepatterns 310, 320 located thereon in positions adjacent to whereconnection tabs 425 of solar cells 400 will be located for makingelectrical connection thereto and to connection tabs 415 viaelectrically conductive adhesive patterns 210, 220 when top layer 200and rear sheet 300 are stacked and heat laminated together to melt flowtop layer 200 including adhesive patterns 210, 220, 250 and rear sheet300 including adhesive patterns 310, 320 to form solar panel 100.

In FIG. 9B, heat laminated solar cell panel 100 is seen to have solarcells 400 embedded in top layer 200 with melt flowable electricallyconductive adhesives having melt flowed around solar cell connectiontabs 415, 425 to make an electrical connection therebetween, wherebyadjacent solar cells 400 are connected in series.

FIG. 10 is a side sectional view of an example embodiment of an examplesolar cell panel 100, FIG. 10A is a side cross-sectional view of aportion thereof, and FIG. 10B is a side view of a tabbing component 430thereof. Solar panel 100 includes plural solar cells 400 encapsulated byheat lamination between a transparent melt flowable thermoplastic topsheet 200 and a layered or laminated rear sheet 300 which includes amelt flowable thermally conductive electrically insulating thermoplasticlayer 300 that is backed by a thin metal layer 308 which is between twothin fluoro-polymer layers. Electrical connections to the front andbacks of solar cells 400 may be made by any of the arrangementsdescribed, and preferably employ a tab 430 described below.

The edges of solar cell panel 100 are supported by, and are preferablysurrounded by, a frame 110, e.g., an aluminum frame 110, that typicallyhas a pair of inwardly extending flanges 112 that bear against the frontand rear surfaces of laminated layers 200, 300-308 to support thelaminated layers at their edges. Preferably an edge seal 115 is providedat assembly of laminated layers 200, 300-308 and frame 110 to seal theedges of laminated layers 200, 300-308 within frame 110 between flanges112.

In a typical panel 100, top layer 200 may have a thickness of about12-15 mils (about 0.25-0.38 mm or about 250-375 microns) and preferablybe of a type SG7130 melt flowable transparent electrically insulatingthermoplastic available from AI Technology, which may be employed asencapsulant and protection so that a glass sheet may be omitted. If aglass or other front sheet is desired or required, top layer 200 of typeSG7130 and similar thermoplastics can be laminated therewith eitherbefore or after being laminated with solar cells 400 and/or rear sheet300, or top layer 200 may be formed on the glass or other front sheet.

Rear sheet 300 may be of the same material as top sheet 200 or may be ofAI Technology type SG7120 melt flowable electrically insulatingthermoplastic or of AI Technology type SG7133 or type CB7135 meltflowable thermally conductive electrically insulating thermoplastic asmay provide an advantage in lowering the operating temperature of solarcells 400. Thermally conductive thermoplastics like SG7133 and CB7135have good UV resistance and so may be used as an outer rear coating 304.The foregoing thermoplastic polymers have good adhesion to the solarcells 400, and do not require cross linking for strength and so may beprocessed efficiently, e.g., in about one tenth the time of aconventional vacuum laminated panel, as described above. These materialsalso have substantial strength and so permit the overall rear sheet 300to be thinner and lighter than would be necessary with conventionalsolar panel backing materials. Other materials, such as PET, HDPE, PVF,EVA, EPDM and the like may be employed behind rear layer 300 where theydo not contact solar cells 400.

Electrically conductive connections to solar cells 400 may include AITechnology types ST8130, ST8133 and/or ST8150 melt flowable electricallyconductive thermoplastic adhesives applied to sheets 200, 300 in anysuitable manner. Fluoro-polymer layers 304 may be AI Technology typeSG7120, SG7130, SG7133 or SG7150 material which may be laminated with ametal layer, e.g., an aluminum or copper sheet, to provide a back sheet304-308 for solar cell panels. The foregoing thermoplastic polymers havegood adhesion and low contact resistance to the metal contacts of solarcells, and do not require cross linking for strength and so may beprocessed efficiently as described above.

In FIG. 10A are shown details of interconnections between the frontcontact 410 of one solar cell 400 and the back contact of an adjacentsolar cell 400 that employ a tabbing material 430 as shown in FIG. 10B.Tabbing material 430 is a layered structure having a central layer of athin metal conductor 432, e.g., a copper foil or sheet of between about¼ ounce and 2.0 ounce weight (or a thickness of about 0.7 mil to 3 mils,or about 0.02 to 0.08 mm) and of between about 0.04 and 0.2 inch (about1 and 5 mm) in width, and having melt flowable electrically conductivethermoplastic adhesive 434 on both surfaces of metal core 432.Preferably, the metal foil 432 is covered by an oxidation resistantfinish, e.g., a tin, silver, nickel, nickel-tin, or nickel-silverplating.

Electrically conductive adhesive 434 may extend continuously on eitheror both surfaces of metal core 432, or may be on only a portion of thesurfaces thereof where the electrical conductivity of the metal core 432and of the electrically conductive adhesive 434 is sufficient to carrythe expected current with acceptable loss. In one embodiment employingAI Technology type ST8130, ST8133 and/or ST8150 melt flowableelectrically conductive thermoplastic adhesive, only about ten percent(10%) of the surface of metal conductor 432 need be covered by the meltflowable electrically conductive thermoplastic adhesive 434 and theremainder may be covered by an insulating adhesive 436, e.g., AITechnology type SG7120, and/or SG7130 electrically insulatingthermoplastic adhesive. Typically, one area of electrically conductiveadhesive 434, e.g., a circle diameter or square of about 1-8 mils (about0.02-0.2 mm), is employed for each one or two or five, or even each ten,equivalent areas of insulating adhesive.

As a result, the thickness of tabs 430 may be reduced from the typical8-10 mils (−0.25 mm) of soldered tinned copper tabs to about 2-5 mils(about 0.05-0.13 mm) with tabbing 430, thereby to advantageously allowfor correspondingly reducing the thickness of top layer 200, e.g., toabout 5 mils (about 0.13 mm), and thereby to reduce the weight and thecost of materials needed for solar cell panel 100. One example tab 430has a copper core 432 of about 1.5 mils (about 0.04 mm) thickness andthermoplastic adhesive layers 434, 436 of about 1 mil (about 0.025 mm)thickness so that the total thickness of tab 430 is about 3.5 mils(about 0.09 mm). Another example tab 430 has a copper core 432 of about0.7 mils (about 0.02 mm) thickness and thermoplastic adhesive layers434, 436 of about 1 mil (about 0.025 mm) thickness so that the totalthickness of tab 430 is about 2.7 mils (about 0.07 mm).

Lengths of tabbing 430 shorter than the dimension of solar cells 400 maybe employed in the place of conductor patterns 210 of top sheet 200 andof conductor patterns 310 of rear sheet 300 as in the left hand portionof FIG. 10A wherein melt flowing of adhesives 210, 310 join when toplayer 200 or when layers 200, 300 are heat laminated to form connectionsbetween tabs 430, thereby to connect the front contact of a solar cell400 to the back contact of another solar cell 400 as described. Suchtabs 430 may be made on top layer 200 and rear sheet 300 as described,or may be applied to solar cells 400 prior to their being laminated totop sheet 200 and rear sheet 300, or may be made on top layer 200 asdescribed and applied to the backs of solar cells 400 prior to theirbeing laminated to rear sheet 300.

Alternatively, lengths of tabbing 430, e.g., longer than the dimensionof solar cell 400 and shorter than twice that dimension, may be used andapplied to solar cells 400 in similar manner to soldered metal tabs toconnect the front contact of a solar cell 400 to the back contact ofanother solar cell 400. Where tabbing 430 lacks sufficient tackiness toadhere to the contacts of solar cells 400 as required for the handlingthereof, tabs 430 and/or solar cells 400 may be heated so as to obtainsufficient adhesion for handling, e.g., by touching tab 430 with aheated tool such as a soldering iron heated to a temperature sufficientto melt flow adhesive 434, 436, about 140-150° C. as compared to about250° C. needed for soldering.

For certain uses it may be desirable to employ laminate sheets toprovide protection for the front and/or back sides of solar cells 400and panels 100. Where a layer and/or sheet comprises a laminate of alayer of a fluorinated polymer (FP), e.g., PVF and/or PVDF, and/orco-polymers thereof, with a layer or sheet of non-fluorinated polymer(NFP), e.g., PET, EVA, PEN, and/or polyimide, suitable adhesionpromotion should be employed to avoid limited bonding and/or easyde-lamination. Either top layer 200 and/or rear sheet 300, or anotherlayer or sheet applied thereto may comprise a laminate of a layer of,e.g., PVF and/or PVDF, and/or co-polymers thereof, with a layer or sheetof a non-fluorinated polymer, suitable adhesion promoting between layersmay be provided by employing a suitable solvent having a sufficientlylow boiling point. While an adhesion promoting layer may be employed,such layer may not be needed where a suitable adhesion promoting processis employed, thereby simplifying manufacture.

For example, an optional sub-process 580 which is part of process 500 ofFIG. 6 may be employed. Process 580 may be a part of step 510 and/or ofstep 540 of process 500 wherein a layer or sheet of a non-fluorinatedpolymer (NFP), e.g., EVA or PET, is obtained. The fluorinated polymerand/or co-polymer (FP), e.g., PVF or PVDF, may be dissolved intosolution with a solvent, e.g., a N-methyl-2-pyrrolidone (NMP),a ketonesuch as methyl-ethyl ketone (MEK), acetone, or other polar solvent tomake a solution that is as thick as possible for being applied 586 as acoating, e.g., as by drawing down or spraying. Lower boiling point (LBP)solvents are preferred so as to speed completion of the drying process588. The solution is then drawn down, cast, sprayed or otherwise applied586 to coat a substrate polymer layer or sheet, e.g., of PET, PEN, orpolyimide, to the desired thickness, e.g., a thickness of about 25-500microns (about 0.025-0.5 mm, or about 1-20 mils), followed by drying 588to drive out the solvent at a suitable rate that avoids bubble or voidcreation, e.g., drying 588 at ambient temperature or at a highertemperature, e.g., a temperature below its flash point. One or more FPlayers may be applied to the NFP substrate, or a thicker FP layer may beobtained, by repeating steps 584-588 as may be desired, wherein thelayers applied may be of the same fluorinated polymer or of differentfluorinated polymers. The solvent should completely evaporate beforeheat lamination is performed.

The foregoing process 580 may also be employed for providing layers ofnon-fluorinated polymers on a fluorinated polymer substrate. As above,process 580 may be a part of step 510 and/or of step 540 of process 500wherein a layer or sheet of a fluorinated polymer (FP), e.g., PVF orPVDF or their copolymers and blends thereof, is obtained. Thenon-fluorinated polymer and/or co-polymer (NFP), e.g., PET or EVA, maybe dissolved into solution with a solvent, e.g., a MEK or NMP or othersuitable solvent, to make a solution that is as thick as possible forbeing applied 586 as a coating, e.g., as by drawing down or spraying.Lower boiling point (LBP) solvents are preferred so as to speedcompletion of the drying process 588. The solution is then drawn down,cast, sprayed or otherwise applied 586 to coat a substrate polymer layeror sheet, e.g., of PVF or PVDF or blends or copolymers thereof, to thedesired thickness, e.g., a thickness of about 25-500 microns (about0.025-0.5 mm, or about 1-20 mils), followed by drying 588 to drive outthe solvent at a suitable rate that avoids bubbling or void creation,e.g., at ambient or a higher temperature. One or more NFP layers may beapplied to the FP substrate, or a thicker NFP layer may be obtained, byrepeating steps 584-588 as may be desired, wherein the layers appliedmay be of the same fluorinated polymer or of different fluorinatedpolymers.

The foregoing process 580 may also be employed for providing layers offilled polymers, e.g., pigmented, electrically conductive, and/orthermally conductive fluorinated polymers, either on a non-fluorinatepolymer substrate or on a fluorinated polymer substrate.

Suitable melt flowable materials for rear sheets 300 may also includelaminated back sheets comprising a sheet of PET laminated between sheetsof modified PVDF or blends or copolymers thereof, such as SOLARBLOC™ UVresistant back film laminates, e.g., type SG7133, available from AITechnology, Inc. located in Princeton Junction, N.J. AI technology backfilm laminates such as types BF7110 and BF7140 laminates melt flow at atemperature above about 110° C. and above about 140° C., respectively,and are heat laminatable, e.g., at a pressure greater than about 15 psifor about 0.5 second or longer. In addition, SOLARBLOC™ moisture barriercoatings types SB7122, SG7133, SB9122 may be employed for providing amoisture barrier seal or layer, e.g., on the exposed surface of toplayer 200 or on the exposed surface of rear sheet 300, or around a solarpanel frame or other structure.

Suitable electrically conductive adhesives include, e.g., AI TechnologySOLARTAB™ UV resistant electrically conductive adhesive, e.g., typesST8150 and ST8130 conductive tab adhesive, which may be employed for theconductive patterns 210, 220, 310, 320 connecting to the front and backcontacts of solar cells 400. Type ST8150 adhesive melt flows at atemperature greater than about 140° C. and is heat laminatable, e.g., ata pressure greater than about 10 psi for about 0.5 second or longer.

Suitable PVDF polymer materials include KYNAR® 9301, 2500, 2750, and2800 fluoropolymers, and blends and copolymers thereof, which may beobtained from Arkema, Inc. having an office in King of Prussia, Pa., andsimilar PVDF copolymers.

It is noted that only the exposed surface of rear sheet 300 need includea fluorinated polymer; the inner layer or layers may include a highmoisture barrier thermoplastic, e.g., PET, or a thermoset rubber, e.g.,ethylene propylene diene monomer (EPDM) rubber. One preferred innerlayer is an AI Technology type SG7113 thermoplastic which can melt flowand conform very quickly at a temperature of about 130-160° C.,typically in an about 5-15 mils (about 0.13-0.4 mm) thick layer. Whenboth top sheet 200 and rear sheet 300 are of the preferredthermoplastics, e.g., a top sheet 200 of AI Technology type SG7130transparent insulating thermoplastic and a rear sheet 300 of AITechnology type SG7113 or SG7133 insulating thermoplastic, the fulladvantage, e.g., in time and cost savings, flowing from very quickmelting and flowing may be realized. With the preferred materials, e.g.,the melt flowing 530, 560 can be completed in less than about 1-5minutes with or without vacuum.

A laminated module 100, 200 of solar cells 400 having front and backsurfaces may comprise: a top layer 200 of a melt flowed melt flowableoptically transparent electrically insulating thermoplastic adhesivematerial having a first pattern 210, 220 of melt flowable electricallyconductive thermoplastic adhesive thereon for making electricalconnection to the front surfaces of solar cells 400; a plurality ofsolar cells 400 having front and back surfaces to which electricalconnection may be made, the plurality of solar cells 400 being laminatedinto the melt flowed top layer 200 with the first pattern 210, 220 s ofmelt flowable electrically conductive thermoplastic adhesive makingelectrical connection to the front surfaces of the plurality of solarcells 400, whereby light may pass through the melt flowed opticallytransparent top layer 200 to impinge upon the front surface of theplurality of solar cells 400; a rear sheet 300 of a melt flowed meltflowable electrically insulating thermoplastic adhesive material havinga second pattern 310, 320 of melt flowable electrically conductivethermoplastic adhesive thereon for making electrical connection to theback surfaces of the plurality of solar cells 400, the melt flowed rearsheet 300 being laminated to the melt flowed top layer 200 and to theback surfaces of the plurality of solar cells 400 therein with thesecond patterns of melt flowable electrically conductive thermoplasticadhesive making electrical connection to the back surfaces of theplurality of solar cells 400; wherein the first and second patterns 210,220, 310, 320 of melt flowable electrically conductive thermoplasticadhesive are melt flowed to each other to provide an electricalconnection between the front surface of one of the plurality of solarcells 400 and the back surface of another of the plurality of solarcells 400, whereby ones of the plurality of solar cells 400 areelectrically connected in series by the connection between the first andsecond patterns 210, 220, 310, 320 of electrically conductivethermoplastic adhesive. The first pattern 210, 220 may include: a firstpattern 210, 220 of an electrically conductive metal on the top layer200 in the first pattern 210, 220 and the first pattern 210, 220 of meltflowable electrically conductive thermoplastic adhesive disposed on thefirst pattern 210, 220 of electrically conductive metal. The firstpattern 210, 220 may include: an insulating pattern 250 of a meltflowable electrically insulating thermoplastic adhesive on the firstpattern 210, 220 of melt flowable electrically conductive thermoplasticadhesive, wherein the insulating pattern 250 has a plurality ofelongated areas at locations corresponding to locations at which edgesof the plurality of solar cells 400 are to be placed. The second pattern310, 320 may include: a second pattern 310, 320 of an electricallyconductive metal on the rear sheet 300 in the second pattern 310, 320and the second pattern 310, 320 of melt flowable electrically conductivethermoplastic adhesive disposed on the second pattern 310, 320 ofelectrically conductive metal. The first and second patterns 210, 220,310, 320 of melt flowable electrically conductive thermoplastic adhesiveeach include respective portions extending beyond edges of the pluralityof solar cells 400, and wherein the respective extended portions thereofare melt flowed to each other to provide the electrical connectionbetween the front surface of one of the plurality of solar cells 400 andthe back surface of another of the plurality of solar cells 400. Each ofthe plurality of solar cells 400 may include a transparent electricallyconductive front contact substantially covering the front surfacethereof and the first pattern 210, 220 may include for each of theplurality of solar cells 400 at least one elongated conductor 210 havinga plurality of relatively narrower elongated conductors 214 extendingsubstantially perpendicular thereto for making an electrical connectionto the front contact of the solar cell 400; or each of the plurality ofsolar cells 400 may include at least one elongated electricallyconductive front contact 210 on the front surface thereof and the firstpattern 210, 220 includes for each of the plurality of solar cells 400at least one elongated conductor 210 corresponding to the at least oneelongated electrically conductive front contact of the solar cell 400and located for making an electrical connection to the front contact ofthe solar cell 400; or each of the plurality of solar cells 400 mayinclude at least two parallel elongated electrically conductive frontcontacts on the front surface thereof and the first pattern 210, 220includes for each of the plurality of solar cells 400 at least twoparallel elongated conductors 210 corresponding to the at least twoparallel elongated electrically conductive front contacts of the solarcell and located for making an electrical connection to the frontcontacts of the solar cell. The first pattern 210, 220 of melt flowableelectrically conductive thermoplastic adhesive or the second pattern310, 320 of melt flowable electrically conductive thermoplastic adhesiveor both may comprise: at least one elongated continuous strip 210 ofmelt flowable electrically conductive thermoplastic adhesive where theplurality of solar cells 400 do not have a metalized contact on thefront surface and/or on the back surface thereof; or a plurality ofareas 434 may comprise between about ten percent and 100 percent of thearea of metalized contact where the plurality of solar cells 400 have ametalized contact on the front surface and/or on the back surfacethereof. Wherein each of the plurality of solar cells 400 includes anelectrically conductive tab 415, 425, 430 applied to a contact on thefront surface or on the back surface thereof or on both surfacesthereof, the tab 415, 425, 430 extending beyond an edge of the solarcell, the electrically conductive tab 415, 425, 430 may include: asolderable metal strip 415, 425 soldered to a metalized contact of thesolar cell 400; or a metal strip 432 having on opposing broad surfacesthereof a plurality of areas 434 may comprise melt flowable electricallyconductive thermoplastic adhesive covering between about ten percent and100 percent of the area of the metal strip and melt flowableelectrically insulating thermoplastic adhesive substantially coveringthe remaining area 436 of the metal strip 432. The laminated module 100,200 of solar cells 400 may further comprise: a glass layer 208 on anexposed front surface of the melt flowable optically transparent toplayer 200; or a melt flowable optically transparent fluorinated polymerfront layer 206 on an exposed front surface of the melt flowableoptically transparent top layer 200; or a thermally conductive layer 308on an exposed rear surface of the melt flowable rear sheet 300; or anultraviolet resistant melt flowable layer 304, 308 on an exposed rearsurface of the melt flowable rear sheet 300; or any combination of theforegoing. In laminated module 100, 200 of solar cells 400: the toplayer 200 may not be as thick as is the rear sheet 300; or the top layer200 may be at least as thick as are the solar cells 400; or the toplayer 200 may not be as thick as is the rear sheet 300 and may be atleast as thick as are the solar cells 400. The laminated module 100, 200of solar cells 400 may comprise a laminated solar cell panel. Thethermoplastic adhesives of the top layer 200, of the first pattern 210,220 of thermoplastic adhesive, of the rear sheet 300 and of the secondpattern 310, 320 of thermoplastic adhesive, may comprise a molecularlyflexible thermoplastic adhesive having a melt flow temperature in therange between about 80° C. and about 200° C. and having a glasstransition temperature of less than about 0° C.

A laminated module 100, 200 of solar cells 400 having front and backsurfaces may comprise: a top layer 200 of a melt flowed melt flowableoptically transparent electrically insulating thermoplastic adhesivematerial having a first pattern 210, 220 of melt flowable electricallyconductive thermoplastic adhesive thereon for making electricalconnection to the front surfaces of solar cells 400; a plurality ofsolar cells 400 having front and back surfaces to which electricalconnection may be made, the plurality of solar cells 400 being laminatedinto the melt flowed top layer 200 with the first pattern 210, 220 s ofmelt flowable electrically conductive thermoplastic adhesive makingelectrical connection to the front surfaces of the plurality of solarcells 400, and the back surfaces of the plurality of solar cells 400being exposed, whereby light may pass through the melt flowed opticallytransparent top layer 200 to impinge upon the front surface of theplurality of solar cells 400 and connection may be made to the backsurfaces thereof; wherein the first pattern 210, 220 of melt flowableelectrically conductive thermoplastic adhesive melt flowed to provideexposed electrical connections to the front surfaces of the plurality ofsolar cells 400, and wherein the back surfaces of the plurality of solarcells 400 are exposed for making electrical connection thereto, wherebyelectrical connections to the front and back surfaces of the pluralityof solar cells 400 are exposed on the same surface of the laminatedmodule 100, 200 of solar cells 400. The laminated module 100, 200 ofsolar cells 400 may further comprise: a rear sheet 300 of a melt flowedmelt flowable electrically insulating thermoplastic adhesive materialhaving a second pattern 310, 320 of melt flowable electricallyconductive thermoplastic adhesive thereon for making electricalconnection to the back surfaces of the plurality of solar cells 400,wherein the second pattern 310, 320 of melt flowable electricallyconductive thermoplastic adhesive includes a portion extending beyondthe plurality of solar cells 400; the melt flowed rear sheet 300 beinglaminated to the melt flowed top layer 200 and to the back surfaces ofthe plurality of solar cells 400 therein with the second patterns 210,220, 310, 320 of melt flowable electrically conductive thermoplasticadhesive making electrical connection to the back surfaces of theplurality of solar cells 400; wherein the respective portions of thefirst and second patterns 210, 220, 310, 320 of melt flowableelectrically conductive thermoplastic adhesive that extend beyond theplurality of solar cells 400 are melt flow laminated to each other toprovide an electrical connection between the front surface of one of theplurality of solar cells 400 and the back surface of another of theplurality of solar cells 400, whereby ones of the plurality of solarcells 400 are electrically connected in series by the connection betweenthe first and second patterns 210, 220, 310, 320 of electricallyconductive thermoplastic adhesive. The first pattern 210, 220 mayinclude: a first pattern 210, 220 of an electrically conductive metal onthe top layer 200 in the first pattern 210, 220 and the first pattern210, 220 of melt flowable electrically conductive thermoplastic adhesivedisposed on the first pattern 210, 220 of electrically conductive metal.The first pattern 210, 220 may include: an insulating pattern 250 of amelt flowable electrically insulating thermoplastic adhesive on thefirst pattern 210, 220 of melt flowable electrically conductivethermoplastic adhesive, wherein the insulating pattern 250 has aplurality of elongated areas at locations corresponding to locations atwhich edges of the plurality of solar cells 400 are to be placed. Thefirst pattern 210, 220 of melt flowable electrically conductivethermoplastic adhesive may include portions extending beyond edges ofthe plurality of solar cells 400 and exposed near the back surfaces ofthe plurality of solar cells 400 to provide the exposed electricalconnections to the front surfaces of the plurality of solar cells 400.Each of the plurality of solar cells 400 may include a transparentelectrically conductive front contact substantially covering the frontsurface thereof and the first pattern 210, 220 may include for each ofthe plurality of solar cells 400 at least one elongated conductor 210having a plurality of relatively narrower elongated conductors 214extending substantially perpendicular thereto for making an electricalconnection to the front contact of the solar cell 400; or each of theplurality of solar cells 400 may include at least one elongatedelectrically conductive front contact on the front surface thereof andthe first pattern 210, 220 may include for each of the plurality ofsolar cells 400 at least one elongated conductor 210 corresponding tothe at least one elongated electrically conductive front contact of thesolar cell 400 and located for making an electrical connection to thefront contact of the solar cell 400; or each of the plurality of solarcells 400 includes at least two parallel elongated electricallyconductive front contacts 410 on the front surface thereof and the firstpattern 210, 220 includes for each of the plurality of solar cells 400at least two parallel elongated conductors 210 corresponding to the atleast two parallel elongated electrically conductive front contacts 410of the solar cell 400 and located for making an electrical connection tothe front contacts 410 of the solar cell 400. The first pattern 210, 220of melt flowable electrically conductive thermoplastic adhesive maycomprise: at least one elongated continuous strip 210 of melt flowableelectrically conductive thermoplastic adhesive where the plurality ofsolar cells 400 do not have a metalized contact on the front surfacethereof; or a plurality of areas 434 may comprise between about tenpercent and 100 percent of the area of metalized contact 410 where theplurality of solar cells 400 have a metalized contact on the frontsurface thereof. Wherein each of the plurality of solar cells 400includes an electrically conductive tab 415, 425, 430 applied to acontact on the front surface or on the back surface thereof or on bothsurfaces thereof, the tab 415, 425, 430 extending beyond an edge of thesolar cell 400, the electrically conductive tab 415, 425, 430 mayinclude: a solderable metal strip 415, 425 soldered to a metalizedcontact 410 of the solar cell 400; or a solderable metal strip 415, 425soldered to a metalized contact 410 on the front surface of one solarcell 400 and to a metalized contact on the back surface of an adjacentsolar cell 400; or a metal strip 432 having on opposing broad surfacesthereof a plurality of areas 434 may comprise melt flowable electricallyconductive thermoplastic adhesive covering between about ten percent and100 percent of the area of the metal strip and melt flowableelectrically insulating thermoplastic adhesive substantially coveringthe remaining area 436 of the metal strip 432; or a metal strip 432having on opposing broad surfaces thereof a plurality of areas 434 maycomprise melt flowable electrically conductive thermoplastic adhesivecovering between about ten percent and 100 percent of the area of themetal strip and melt flowable electrically insulating thermoplasticadhesive substantially covering the remaining area 436 of the metalstrip 432, wherein areas 434 of melt flowable electrically conductivethermoplastic adhesive on one surface of the metal strip 432 adhere to ametalized contact 410 on the front surface of one solar cell 400 andareas 434 of melt flowable electrically conductive thermoplasticadhesive on the other surface of the metal strip 432 adhere to ametalized contact on the back surface of an adjacent solar cell 400. Thelaminated module 100, 200 of solar cells 400 may further comprise: aglass layer 208 on an exposed front surface of the melt flowableoptically transparent top layer 200; or a melt flowable opticallytransparent fluorinated polymer front layer 206 on an exposed frontsurface of the melt flowable optically transparent top layer 200; or amelt flowable optically transparent fluorinated polymer front layer 206on an exposed front surface of the melt flowable optically transparenttop layer 200 and a glass layer 208 on an exposed front surface of themelt flowable optically transparent polymer front layer 206. The meltflowable optically transparent fluorinated polymer layer may be of adifferent material than is the melt flowable optically transparent toplayer 200; or the melt flowable optically transparent fluorinatedpolymer layer may be of a different material than is the melt flowableoptically transparent top layer 200 and the melt flowable opticallytransparent fluorinated polymer layer and the melt flowable opticallytransparent top layer 200 may have respective melt flow temperatures inabout the same temperature range. The melt flowable top layer 200 may beat least as thick as are the solar cells 400. The thermoplasticadhesives of the top layer 200 and of the first pattern 210, 220 ofthermoplastic adhesive may comprise a molecularly flexible thermoplasticadhesive having a melt flow temperature in the range between about 80°C. and about 200° C. and having a glass transition temperature of lessthan about 0° C.

A laminated module 100, 200 of solar cells 400 having front and backsurfaces may comprise: a top layer 200 of a melt flowed melt flowableoptically transparent electrically insulating molecularly flexiblethermoplastic adhesive material having at least ten percent molecularcrystallites that melt flow at a temperature in the range between about80° C. and about 250° C. and having a glass transition temperature ofless than about 0° C.; to bond to the front surfaces of solar cells 400;a rear sheet 300 of a melt flowed melt flowable electrically insulatingmolecularly flexible thermoplastic adhesive material having at least tenpercent molecular crystallites that melt flow at a temperature in therange between about 80° C. and about 250° C. and having a glasstransition temperature of less than about 0° C.; to bond to the backsurfaces of solar cells 400; a plurality of solar cells 400 having frontand back surfaces to which electrical connection may be made, theplurality of solar cells 400 being encapsulated by the molecularlyflexible thermoplastic adhesives of the melt flowed top layer 200 and ofthe melt flowed rear sheet 300; electrically conductive interconnectionmembers 210, 220, 310, 320, 415, 425, 430 providing electricalconnections between the front surfaces of ones of the plurality of solarcells 400 and the back surfaces of others of the plurality of solarcells 400; wherein the melt flowable molecularly flexible thermoplasticadhesive of the top layer 200 is bonded to the front surfaces of theplurality of solar cells 400 and the melt flowable molecularly flexiblethermoplastic adhesive of the rear sheet 300 is bonded to the backsurfaces of the plurality of solar cells 400, whereby light may passthrough the melt flowed optically transparent top layer 200 to impingeupon the front surface of the plurality of solar cells 400; wherein thelaminated module 100, 200 including the top layer 200 and the rear sheet300 exhibits a flexural modulus at about 60° C. that is at least fiftypercent of the flexural modulus exhibited at about 20° C. withoutcross-linking chemical curing. The interconnection members 210, 220,310, 320, 415, 425, 430 may comprise: a first pattern 210, 220 of meltflowable electrically conductive thermoplastic adhesive on the top layer200 making electrical connection to the front surfaces of the pluralityof solar cells 400; a second pattern 310, 320 of melt flowableelectrically conductive thermoplastic adhesive on the rear sheet 300making electrical connection to the back surfaces of the plurality ofsolar cells 400, each of the first and second patterns 210, 220, 310,320 of melt flowable electrically conductive thermoplastic adhesiveincluding respective portions extending beyond the edges of theplurality of solar cells 400 that are melt flow connected to each otherto provide an electrical connection between the front surface of one ofthe plurality of solar cells 400 and the back surface of another of theplurality of solar cells 400, whereby ones of the plurality of solarcells 400 are electrically connected in series by the connection betweenthe first and second patterns 210, 220, 310, 320 of electricallyconductive thermoplastic adhesive. The interconnection members 210, 220,310, 320, 415, 425, 430 may comprise: at least one elongated continuousstrip 210, 220, 310, 320 of melt flowable electrically conductivethermoplastic adhesive where the plurality of solar cells 400 do nothave a metalized contact on the front surface and/or on the back surfacethereof; or a plurality of areas 434 may comprise between about tenpercent and 100 percent of the area of metalized contact where theplurality of solar cells 400 have a metalized contact on the frontsurface and/or on the back surface thereof. The interconnection members210, 220, 310, 320, 415, 425, 430 may comprise: an electricallyconductive tab 415, 425, 430 applied to a contact 410 on the frontsurface or on the back surface of or on both surfaces of each of theplurality of solar cells 400, each tab 415, 425, 430 extending beyond anedge of the solar cell 400, wherein the electrically conductive tab 415,425, 430 may includes: a solderable metal strip 415, 425 soldered to ametalized contact 410 of the solar cell 400; or a metal strip 432 havingon opposing broad surfaces thereof a plurality of areas 434 may comprisemelt flowable electrically conductive thermoplastic adhesive coveringbetween about ten percent and 100 percent of the area of the metal strip432 and melt flowable electrically insulating thermoplastic adhesivesubstantially covering the remaining area 436 of the metal strip 432.The interconnection members 210, 220, 310, 320, 415, 425, 430 maycomprise: solderable metal strips 415, 425 soldered to metalizedcontacts 410 of the plurality of solar cells 400; or metal strips 432each having on opposing broad surfaces thereof a plurality of areas 434may comprise melt flowable electrically conductive thermoplasticadhesive covering between about ten percent and 100 percent of the areaof the metal strip 432 and melt flowable electrically insulatingthermoplastic adhesive substantially covering the remaining area 436 ofthe metal strip 432.

A method 500 for making a laminated module 100, 200 of solar cells 400having front and back surfaces may comprise: obtaining 510 a top layer200 of a melt flowable optically transparent electrically insulatingthermoplastic adhesive material having a first pattern 210, 220 of meltflowable electrically conductive thermoplastic adhesive thereon formaking electrical connection to the front surface of solar cells 400;placing 520 a plurality of solar cells 400 having front and backsurfaces to which electrical connection may be made on the melt flowabletop layer 200 in locations with the first pattern 210, 220 of meltflowable electrically conductive thermoplastic adhesive adjacent thefront surfaces of the plurality of solar cells 400, whereby anelectrical connection may be made between the first pattern 210, 220 ofmelt flowable electrically conductive thermoplastic adhesive and thefront surfaces of the plurality of solar cells 400; obtaining 540 a rearsheet 300 of a melt flowable electrically insulating thermoplasticadhesive material having a second pattern 310, 320 of melt flowableelectrically conductive thermoplastic adhesive thereon for makingelectrical connection to the rear surface of the solar cells 400;placing 550 the melt flowable rear sheet 300 adjacent to the meltflowable top layer 200 and the back surfaces of the plurality of solarcells 400 in a location with the second pattern 310, 320 of meltflowable electrically conductive thermoplastic adhesive adjacent theback surfaces of the plurality of solar cells 400; heat laminating 530,560 the melt flowable top layer 200, the plurality of solar cells 400and the melt flowable rear sheet 300 to melt flow the melt flowable toplayer 200 and the melt flowable rear sheet 300 together so thatelectrical connections are made between the first pattern 210, 220 ofmelt flowable electrically conductive thermoplastic adhesive and thefront surfaces of the plurality of solar cells 400, between the secondpattern 310, 320 of melt flowable electrically conductive thermoplasticadhesive and the back surfaces of the plurality of solar cells 400, andbetween the first and second patterns 210, 220, 310, 320 of pattern ofmelt flowable electrically conductive thermoplastic adhesive; wherebythe plurality of solar cells 400 are embedded into at least the meltflowable top layer 200, and whereby ones of the plurality of solar cells400 are electrically connected in series by the connection between thefirst and second patterns 210, 220, 310, 320 of electrically conductivethermoplastic adhesive. The obtaining 510 a top layer 200 of a meltflowable optically transparent electrically insulating thermoplasticadhesive material may include: applying 514 the first pattern 210, 220of melt flowable electrically conductive thermoplastic adhesive on onesurface of the top layer 200 of melt flowable optically transparentelectrically insulating thermoplastic adhesive material, wherein thefirst pattern 210, 220 includes at least one elongated conductor 210,220 for making electrical connection to the front surface of solar cells400. The applying 514, 516 the first pattern 210, 220 may include:applying 514 the first pattern 210, 220 of melt flowable electricallyconductive thermoplastic adhesive by screening, stenciling, rollcoating, masking, deposition, printing, screen printing, inkjetprinting, or sheet laminating; or patterning an electrically conductivemetal on the sheet in the first pattern 210, 220 and applying 514 thefirst pattern 210, 220 of melt flowable electrically conductivethermoplastic adhesive on the patterned electrically conductive metal byscreening, stenciling, roll coating, masking, deposition, printing,screen printing, inkjet printing, or sheet laminating. Applying 514, 516the first pattern 210, 220 may include: applying 516 an insulatingpattern of a melt flowable electrically insulating thermoplasticadhesive 250 on the first pattern 210, 220 of melt flowable electricallyconductive thermoplastic adhesive, wherein the insulating pattern 250has a plurality of elongated areas 250 at locations corresponding tolocations at which the edges of the plurality of solar cells 400 are tobe placed. The method 500 wherein: the placing 520 a plurality of solarcells 400 may include placing solar cells 400 in locations with portionsof the first pattern 210, 220 of melt flowable electrically conductivethermoplastic adhesive extending beyond edges of the plurality of solarcells 400; and the placing 550 the melt flowable rear sheet 300 adjacentto the melt flowable top layer 200 may include placing 550 the rearsheet 300 in a location with portions of the second pattern 310, 320 ofmelt flowable electrically conductive thermoplastic adhesive extendingbeyond edges of the plurality of solar cells 400 opposite the extendingportions of the first pattern 210, 220 of electrically conductivethermoplastic adhesive; wherein electrical connections are made betweenthe respective extending portions of the first and second patterns 210,220, 310, 320 of pattern of melt flowable electrically conductivethermoplastic adhesive. The obtaining 540 a rear sheet 300 of a meltflowable electrically insulating thermoplastic adhesive material mayinclude: applying 544 the second pattern 310, 320 of melt flowableelectrically conductive thermoplastic adhesive on one surface of therear sheet 300 of melt flowable electrically insulating thermoplasticadhesive material, wherein the second pattern 310, 320 includes at leastone conductor 310, 320 for making electrical connection to the backsurface of solar cells 400. The applying the second pattern 310, 320 mayinclude: applying 544 the second pattern 310, 320 of melt flowableelectrically conductive thermoplastic adhesive by screening, stenciling,roll coating, masking, deposition, printing, screen printing, inkjetprinting, or sheet laminating; or patterning an electrically conductivemetal on the sheet in the second pattern 310, 320 and applying 544 thesecond pattern 310, 320 of melt flowable electrically conductivethermoplastic adhesive on the patterned electrically conductive metal byscreening, stenciling, roll coating, masking, deposition, printing,screen printing, inkjet printing, or sheet laminating. The placing 520 aplurality of solar cells 400 may include: placing 520 the front surfacesof the solar cells 400 adjacent to the first pattern 210, 220 of meltflowable electrically conductive thermoplastic adhesive while the meltflowable electrically conductive thermoplastic adhesive is wet; orplacing 520 the front surfaces of the solar cells 400 adjacent to thefirst pattern 210, 220 of melt flowable electrically conductivethermoplastic adhesive after the melt flowable electrically conductivethermoplastic adhesive is dried; or placing 520 the front surfaces ofthe solar cells 400 adjacent to the first pattern 210, 220 of meltflowable electrically conductive thermoplastic adhesive after the meltflowable electrically conductive thermoplastic adhesive is B-staged. Themethod 500 wherein: each of the plurality of solar cells 400 includes atransparent electrically conductive front contact substantially coveringthe front surface thereof and the first pattern 210, 220 includes foreach of the plurality of solar cells 400 at least one elongatedconductor 210, 220 having a plurality of relatively narrower elongatedconductors 214 extending substantially perpendicular thereto for makingan electrical connection to the front contact of the solar cell; or eachof the plurality of solar cells 400 includes at least one elongatedelectrically conductive front contact 410 on the front surface thereofand the first pattern 210, 220 includes for each of the plurality ofsolar cells 400 at least one elongated conductor 210, 220 correspondingto the at least one elongated electrically conductive front contact 410of the solar cell 400 and located for making an electrical connection tothe front contact 410 of the solar cell 400; or each of the plurality ofsolar cells 400 includes at least two parallel elongated electricallyconductive front contacts 410 on the front surface thereof and the firstpattern 210, 220 includes for each of the plurality of solar cells 400at least two parallel elongated conductors 210, 220 corresponding to theat least two parallel elongated electrically conductive front contacts410 of the solar cell 400 and located for making an electricalconnection to the front contacts 410 of the solar cell 400. Each of theplurality of solar cells 400 may have a contact 410 on the front surfacethereof to which electrical connection may be made, wherein the placing520 a plurality of solar cells 400 on the melt flowable top layer 200includes heating the top layer 200, the solar cells 400, or both, so asto increase the adhesion of the solar cells 400 to the top layer 200.The first pattern 210, 220 of melt flowable electrically conductivethermoplastic adhesive or the second pattern 310, 320 of melt flowableelectrically conductive thermoplastic adhesive or both may comprise: atleast one elongated continuous strip 210, 220, 310, 320 of melt flowableelectrically conductive thermoplastic adhesive where the plurality ofsolar cells 400 do not have a metalized contact on the front surfaceand/or on the back surface thereof; or a plurality of areas 434 maycomprise between about ten percent and 100 percent of the area ofmetalized contact 410 where the plurality of solar cells 400 have ametalized contact 410 on the front surface and/or on the back surfacethereof. Each of the plurality of solar cells 400 may include anelectrically conductive tab 415, 425, 430 applied to a contact 410 onthe front surface or on the back surface thereof or on both surfacesthereof, the tab 415, 425, 430 extending beyond an edge of the solarcell 400, and the electrically conductive tab 415, 425, 430 may include:a solderable metal strip 415, 425, soldered to a metalized contact 410of the solar cell 400; or a metal strip 432 having on opposing broadsurfaces thereof a plurality of areas 434 may comprise melt flowableelectrically conductive thermoplastic adhesive covering between aboutten percent and 100 percent of the area of the metal strip 432 and meltflowable electrically insulating thermoplastic adhesive substantiallycovering the remaining area 436 of the metal strip 432. The heatlaminating 530, 560 may include: heat laminating 530 the melt flowabletop layer 200 and the plurality of solar cells 400 thereon to melt flowthe melt flowable top layer 200 so that electrical connections are madebetween the first pattern 210, 220 of melt flowable electricallyconductive thermoplastic adhesive and the front surfaces of theplurality of solar cells 400 and the plurality of solar cells 400 areembedded into the melt flowable top layer 200. The heat laminating 530,560 may include: heat laminating 560 the melt flowed top layer 200 withthe plurality of solar cells 400 embedded therein and the melt flowablerear sheet 300 to melt flow the melt flowable top layer 200 and the meltflowable rear sheet 300 together so that electrical connections are madebetween the second pattern 310, 320 of melt flowable electricallyconductive thermoplastic adhesive and the back surfaces of the pluralityof solar cells 400, and between the respective extending portions of thefirst and second patterns 210, 220, 310, 320 of pattern of melt flowableelectrically conductive thermoplastic adhesive; whereby ones of theplurality of solar cells 400 are electrically connected in series by theconnection between the first and second patterns 210, 220, 310, 320 ofelectrically conductive thermoplastic adhesive. The heat laminating 530,560 may include: heat laminating 530, 560 a glass layer 208 on anexposed front surface of the melt flowable optically transparent toplayer 200; or heat laminating 530, 560 a thermally conductive layer 304,308 on an exposed rear surface of the melt flowable rear sheet 300; orheat laminating 530, 560 a glass layer 208 on an exposed front surfaceof the melt flowable optically transparent top layer 200 and a thermallyconductive layer 304, 308 on an exposed rear surface of the meltflowable rear sheet 300. The heat laminating 530, 560 may comprise:rolling heat laminating 530, 560; or rolling heat laminating 530, 560employing heated laminating rollers 610; or rolling heat laminating 530,560 employing a release liner 536, 566 between at least the top layer200 and the laminating rollers 610; or rolling heat laminating 530, 560employing a release liner 536, 566 between at least the rear sheet 300and the laminating rollers 610; or rolling heat laminating 530, 560employing one or more heating elements 630 for heating at least the toplayer 200 prior to the laminating rollers 610; or rolling heatlaminating 530, 560 employing one or more heating elements 630 forheating at least the rear sheet 300 prior to the laminating rollers 610;or vacuum laminating; or any combination of the foregoing. The heatlaminating 530, 560 may further comprise: placing 534, 564 a releaseliner adjacent at least the top layer 200; and placing a backing sheetthat is stiffer than the top layer 200 against the release liner 536,566 for defining a surface to which the top layer 200 conforms when heatlaminated 530, 560. The obtaining 510 a top layer 200 may includeobtaining 510 a roll or sheet including a plurality of top layers 200,and the method 500 may further comprise: separating 570 a roll laminated530, 560 roll or sheet including a plurality of top layers 200 into aplurality of individual top layers 200. The obtaining 540 a rear sheet300 may include obtaining 540 a roll or sheet including a plurality ofrear sheets 300, and the method 500 may further comprise: separating 570a roll laminated 530, 560 roll or sheet including a plurality of rearsheets 300 into a plurality of individual rear sheets 300. The laminatedmodule 100, 200 of solar cells 400 may comprise a laminated 530, 560solar cell panel 100.

A method 500 for making a laminated module 100, 200 of solar cells 400having front and back surfaces may comprise: obtaining 510 a top layer200 of a melt flowable optically transparent electrically insulatingthermoplastic adhesive material having a first pattern 210, 220 of meltflowable electrically conductive thermoplastic adhesive thereon formaking electrical connection to the front surface of solar cells 400;placing 520 a plurality of solar cells 400 having front and backsurfaces to which electrical connection may be made on the melt flowabletop layer 200 in locations with the first pattern 210, 220 of meltflowable electrically conductive thermoplastic adhesive adjacent thefront surfaces of the plurality of solar cells 400, whereby light maypass through the melt flowable optically transparent top layer 200 toimpinge upon the front surface of the plurality of solar cells 400 andconnection may be made to the back surfaces thereof; heat laminating530, 560 the melt flowable top layer 200 and the plurality of solarcells 400 to melt flow the melt flowable top layer 200 so thatelectrical connections are made between the first pattern 210, 220 ofmelt flowable electrically conductive thermoplastic adhesive and thefront surfaces of the plurality of solar cells 400; wherein theplurality of solar cells 400 are embedded into the melt flowable toplayer 200, wherein the first pattern 210, 220 of melt flowableelectrically conductive thermoplastic adhesive provides exposedelectrical connections to the front surfaces of the plurality of solarcells 400, and wherein the back surfaces of the plurality of solar cells400 are exposed for making electrical connection thereto, wherebyelectrical connections to the front and back surfaces of the pluralityof solar cells 400 are exposed on the same surface of the laminatedmodule 100, 200 of solar cells 400. The method 500 may further comprise:obtaining 540 a rear sheet 300 of a melt flowable electricallyinsulating thermoplastic adhesive material having a second pattern 310,320 of melt flowable electrically conductive thermoplastic adhesivethereon for making electrical connection to the rear surface of thesolar cells 400; placing 550 the melt flowable rear sheet 300 adjacentto the melt flowable top layer 200 and the back surfaces of theplurality of solar cells 400 in a location with the second pattern 310,320 of melt flowable electrically conductive thermoplastic adhesiveadjacent the back surfaces of the plurality of solar cells 400 withportions of the second pattern 310, 320 of melt flowable electricallyconductive thermoplastic adhesive extending beyond edges of theplurality of solar cells 400 opposite the extending portions of thefirst pattern 210, 220 of electrically conductive thermoplasticadhesive; heat laminating 530, 560 the melt flowable top layer 200, theplurality of solar cells 400 and the melt flowable rear sheet 300 tomelt flow the melt flowable top layer 200 and the melt flowable rearsheet 300 together so that electrical connections are made between thesecond pattern 310, 320 of melt flowable electrically conductivethermoplastic adhesive and the back surfaces of the plurality of solarcells 400, and between the respective extending portions of the firstand second patterns 210, 220, 310, 320 of pattern of melt flowableelectrically conductive thermoplastic adhesive; whereby the plurality ofsolar cells 400 are embedded into at least the melt flowable top layer200, and whereby ones of the plurality of solar cells 400 areelectrically connected in series by the connection between the first andsecond patterns 210, 220, 310, 320 of electrically conductivethermoplastic adhesive. The obtaining 510 a top layer 200 of a meltflowable optically transparent electrically insulating thermoplasticadhesive material may include: applying 514 the first pattern 210, 220of melt flowable electrically conductive thermoplastic adhesive on onesurface of the top layer 200 of melt flowable optically transparentelectrically insulating thermoplastic adhesive material, wherein thefirst pattern 210, 220 includes at least one elongated conductor 210,220 for making electrical connection to the front surface of solar cells400. The applying 514 the first pattern 210, 220 may include: applying514 the first pattern 210, 220 of melt flowable electrically conductivethermoplastic adhesive by screening, stenciling, roll coating, masking,deposition, printing, screen printing, inkjet printing, or sheetlaminating; or patterning an electrically conductive metal on the sheetin the first pattern 210, 220 and applying 514 the first pattern 210,220 of melt flowable electrically conductive thermoplastic adhesive onthe patterned electrically conductive metal by screening, stenciling,roll coating, masking, deposition, printing, screen printing, inkjetprinting, or sheet laminating. The applying the first pattern 210, 220may include: applying 516 an insulating pattern 250 of a melt flowableelectrically insulating thermoplastic adhesive on the first pattern 210,220 of melt flowable electrically conductive thermoplastic adhesive,wherein the insulating pattern 250 has a plurality of elongated areas250 at locations corresponding to locations at which the edges of theplurality of solar cells 400 are to be placed. The method 500 wherein:the placing 520 a plurality of solar cells 400 includes placing 520solar cells 400 in locations with portions of the first pattern 210, 220of melt flowable electrically conductive thermoplastic adhesiveextending beyond edges of the plurality of solar cells 400, wherein theportions of the first pattern 210, 220 of melt flowable electricallyconductive thermoplastic adhesive extending beyond solar cells 400 areexposed near the back surfaces of the plurality of solar cells 400 toprovide the exposed electrical connections to the front surfaces of theplurality of solar cells 400. The placing 520 a plurality of solar cells400 may include: placing 520 the front surfaces of the solar cells 400adjacent to the first pattern 210, 220 of melt flowable electricallyconductive thermoplastic adhesive while the melt flowable electricallyconductive thermoplastic adhesive is wet; or placing 520 the frontsurfaces of the solar cells 400 adjacent to the first pattern 210, 220of melt flowable electrically conductive thermoplastic adhesive afterthe melt flowable electrically conductive thermoplastic adhesive isdried; or placing 520 the front surfaces of the solar cells 400 adjacentto the first pattern 210, 220 of melt flowable electrically conductivethermoplastic adhesive after the melt flowable electrically conductivethermoplastic adhesive is B-staged. The method 500 wherein: each of theplurality of solar cells 400 includes a transparent electricallyconductive front contact substantially covering the front surfacethereof and the first pattern 210, 220 includes for each of theplurality of solar cells 400 at least one elongated conductor 210 havinga plurality of relatively narrower elongated conductors 214 extendingsubstantially perpendicular thereto for making an electrical connectionto the front contact of the solar cell 400; or each of the plurality ofsolar cells 400 includes at least one elongated electrically conductivefront contact 410 on the front surface thereof and the first pattern210, 220 includes for each of the plurality of solar cells 400 at leastone elongated conductor 210, 220 corresponding to the at least oneelongated electrically conductive front contact 410 of the solar cell400 and located for making an electrical connection to the front contact410 of the solar cell 400; or each of the plurality of solar cells 400includes at least two parallel elongated electrically conductive frontcontacts 410 on the front surface thereof and the first pattern 210, 220includes for each of the plurality of solar cells 400 at least twoparallel elongated conductors 210, 220 corresponding to the at least twoparallel elongated electrically conductive front contacts 410 of thesolar cell 400 and located for making an electrical connection to thefront contacts 410 of the solar cell 400. The method 500 wherein each ofthe plurality of solar cells 400 has a contact 410 on the front surfacethereof to which electrical connection may be made, wherein the placing520 a plurality of solar cells 400 on the melt flowable top layer 200includes heating the top layer 200, the solar cells 400, or both, so asto increase the adhesion of the solar cells to the top layer 200. Thefirst pattern 210, 220 of melt flowable electrically conductivethermoplastic adhesive may comprise: at least one elongated continuousstrip 210, 220 of melt flowable electrically conductive thermoplasticadhesive where the plurality of solar cells 400 do not have a metalizedcontact on the front surface thereof; or a plurality of areas 434 maycomprise between about ten percent and 100 percent of the area ofmetalized contact 410 where the plurality of solar cells 400 have ametalized contact 410 on the front surface thereof. The method 500wherein each of the plurality of solar cells 400 may include anelectrically conductive tab 415, 425, 430 applied to a contact 410 onthe front surface or on the back surface thereof or on both surfacesthereof, the tab 415, 425, 430 extending beyond an edge of the solarcell 400, and wherein the electrically conductive tab 415, 425, 430 mayinclude: a solderable metal strip 415, 425 soldered to a metalizedcontact 410 of the solar cell 400; or a solderable metal strip 415, 425soldered to a metalized contact 410 on the front surface of one solarcell 400 and to a metalized contact 410 on the back surface of anadjacent solar cell 400; or a metal strip 432 having on opposing broadsurfaces thereof a plurality of areas 434 may comprise melt flowableelectrically conductive thermoplastic adhesive covering between aboutten percent and 100 percent of the area of the metal strip 432 and meltflowable electrically insulating thermoplastic adhesive substantiallycovering the remaining area 436 of the metal strip 432; or a metal strip432 having on opposing broad surfaces thereof a plurality of areas 434may comprise melt flowable electrically conductive thermoplasticadhesive covering between about ten percent and 100 percent of the areaof the metal strip 432 and melt flowable electrically insulatingthermoplastic adhesive substantially covering the remaining area 436 ofthe metal strip 432, wherein areas 434 of melt flowable electricallyconductive thermoplastic adhesive on one surface of the metal strip 432adhere to a metalized contact 410 on the front surface of one solar cell400 and areas 434 of melt flowable electrically conductive thermoplasticadhesive on the other surface of the metal strip 432 adhere to ametalized contact 410 on the back surface of an adjacent solar cell 400.The heat laminating 530, 560 may include: heat laminating 530, 560 aglass layer 208 on an exposed front surface of the melt flowableoptically transparent top layer 200. The method 500 wherein the heatlaminating 530, 560 may comprise: rolling heat laminating 530, 560; orrolling heat laminating 530, 560 employing heated laminating rollers610; or rolling heat laminating 530, 560 employing a release liner 536,536 between at least the top layer 200 and the laminating rollers 610;or rolling heat laminating 530, 560 employing one or more heatingelements 630 for heating at least the top layer 200 prior to thelaminating rollers 610; or vacuum laminating; or any combination of theforegoing. The heat laminating 530, 560 may further comprise: placing534, 564 a release liner 536, 566 adjacent at least the top layer 200;and placing 534, 536 a backing sheet 536, 566 that is stiffer than thetop layer 200 against the release liner 536, 566 for defining a surfaceto which the top layer 200 conforms when heat laminated 530, 560. Theobtaining 510 a top layer 200 may include obtaining 510 a roll or sheetincluding a plurality of top layer 200 s, the method may furthercomprise: separating 570 a roll laminated roll or sheet including aplurality of top layers 200 into a plurality of individual top layers200.

A method 500 for making a laminated module 100, 200 of solar cells 400having front and back surfaces may comprise: obtaining 510 a top layer200 of a melt flowable optically transparent electrically insulatingmolecularly flexible thermoplastic adhesive material having at least tenpercent molecular crystallites that melt flow at a temperature in therange between about 80° C. and about 250° C. and having a glasstransition temperature of less than about 0° C.; to bond to the frontsurfaces of solar cells 400; placing 520 a plurality of solar cells 400having front and back surfaces to which electrical connection may bemade with the front surfaces thereof adjacent the melt flowable toplayer 200; providing electrical connections 210, 220, 310, 320, 415,425, 430 between the front surface of ones of the plurality of solarcells 400 and the back surface of others of the plurality of solar cells400; placing 550 adjacent the back surfaces of the plurality of solarcells 400 and top sheet 200 a rear sheet 300 of a melt flowableelectrically insulating molecularly flexible thermoplastic adhesivematerial having at least ten percent molecular crystallites that meltflow at a temperature in the range between about 80° C. and about 250°C. and having a glass transition temperature of less than about 0° C.;to bond to the back surfaces of solar cells 400; heat laminating 530,560 the melt flowable top layer 200, the plurality of solar cells 400and the melt flowable rear sheet 300 to melt flow the melt flowable toplayer 200 and the melt flowable rear sheet 300 together so that theplurality of solar cells 400 and the electrical connections therebetween are encapsulated in the melt flowed molecularly flexiblethermoplastic adhesive of at least the top layer 200; whereby light maypass through the melt flowed optically transparent top layer 200 toimpinge upon the front surface of the plurality of solar cells 400;wherein the laminated module 100, 200 including the top layer 200 andthe rear sheet 300 exhibits a flexural modulus at about 60° C. that isat least fifty percent of the flexural modulus exhibited at about 20° C.without cross-linking chemical curing. The providing electricalconnections 210, 220, 310, 320, 415, 525, 430 may comprise: providing514 a first pattern 210, 220 of melt flowable electrically conductivethermoplastic adhesive on the top layer 200 in locations for makingelectrical connection to the front surfaces of the plurality of solarcells 400; providing 544 a second pattern 310, 320 of melt flowableelectrically conductive thermoplastic adhesive on the rear sheet 300 inlocations for making electrical connection to the back surfaces of theplurality of solar cells 400, wherein each of the first and secondpatterns 210, 220, 310, 320 of melt flowable electrically conductivethermoplastic adhesive include respective portions extending beyond theedges of the plurality of solar cells 400 that melt flow connect to eachother to provide an electrical connection between the front surface ofone of the plurality of solar cells 400 and the back surface of anotherof the plurality of solar cells 400, whereby ones of the plurality ofsolar cells 400 are electrically connected in series by the connectionbetween the first and second patterns 210, 220, 310, 320 of electricallyconductive thermoplastic adhesive. The providing electrical connections210, 220, 310, 320, 415, 525, 430 may comprise: providing 514 at leastone elongated continuous strip of melt flowable electrically conductivethermoplastic adhesive where the plurality of solar cells 400 do nothave a metalized contact on the front surface and/or on the back surfacethereof; or providing 514 a plurality of areas 434 may comprise betweenabout ten percent and 100 percent of the area of metalized contact 410where the plurality of solar cells 400 have a metalized contact 410 onthe front surface and/or on the back surface thereof. The providingelectrical connections 210, 220, 310, 320, 415, 525, 430 may comprise:applying an electrically conductive tab 415, 525, 430 to a contact 410on the front surface or on the back surface of or on both surfaces ofeach of the plurality of solar cells 400, each tab 415, 525, 430extending beyond an edge of the solar cell, wherein the electricallyconductive tab 415, 525, 430 may include: a solderable metal strip 415,525 soldered to a metalized contact 410 of the solar cell 400; or ametal strip 432 having on opposing broad surfaces thereof a plurality ofareas 434 may comprise melt flowable electrically conductivethermoplastic adhesive covering between about ten percent and 100percent of the area of the metal strip 432 and melt flowableelectrically insulating thermoplastic adhesive substantially coveringthe remaining area 436 of the metal strip 432, attached to a metalizedcontact 410 of the solar cell 400. The providing electrical connections415, 525, 430 may comprise: soldering solderable metal strips 415, 525to metalized contacts 410 of the plurality of solar cells 400; orattaching 530 metal strips 432 having on opposing broad surfaces thereofa plurality of areas 434 may comprise melt flowable electricallyconductive thermoplastic adhesive covering between about ten percent and100 percent of the area of the metal strip 432 and melt flowableelectrically insulating thermoplastic adhesive substantially coveringthe remaining area 436 of the metal strip 432, to metalized contacts 410of the plurality of solar cells 400.

A laminated module 100, 200 of solar cells 400 having front and backsurfaces may comprise: a plurality of solar cells 400 having front andback surfaces to which electrical connection is to be made; a top layer200 of an optically transparent electrically insulating materialadjacent to and having adhesion to the front surfaces of solar cells400, whereby light may pass through the optically transparent top layer200 to impinge upon the front surfaces of the plurality of solar cells400; a thermally conductive rear sheet 300 may include a melt flowedmelt flowable thermally conductive and electrically insulatingthermoplastic adhesive material adjacent to and having adhesion to theback surfaces of solar cells 400; a plurality of electrical connections415, 525, 430, each electrical connection being between the frontsurface of one of the plurality of solar cells 400 and the back surfaceof another of the plurality of solar cells 400, whereby ones of theplurality of solar cells 400 are electrically connected in series; andthe top layer 200, the thermally conductive rear sheet 300 and theplurality of solar cells 400 being melt flow laminated with at least themelt flowed thermally conductive thermoplastic adhesive material of thethermally conductive rear sheet 300 melt flow laminating to theplurality of solar cells 400; the top layer 200 adhering to the frontsurfaces of the plurality of solar cells 400 and the thermallyconductive rear sheet 300 adhering to the back surfaces of the pluralityof solar cells 400, whereby heat from the plurality of solar cells 400can be transferred via the thermally conductive rear sheet 300. Thelaminated module 100, 200 of solar cells 400 may further comprise: athermally conductive metal sheet thermally coupled to an exposed rearsurface of the melt flowable rear sheet 300. The thermally conductivemetal sheet may include a sheet of aluminum or copper or an alloythereof; or the thermally conductive metal sheet may have a thickness ofat least about 2 mils (0.002 inch); or the thermally conductive metalsheet may include a sheet of aluminum or copper or an alloy thereofhaving a thickness of at least about 2 mils (0.002 inch). The thermallyconductive metal sheet may comprise a honeycomb, a perforated laminate,a structural member, or a combination thereof. The melt flowablethermally conductive rear sheet 300 may have a thermal conductivity in arange of about 0.5-4.0 Watt per meter ° K; or the melt flowablethermally conductive rear sheet 300 may have a thermal conductivity ofup to about 20 Watt per meter ° K. The top layer 200, or the rear sheet300, or both, may comprise: a molecularly flexible thermoplasticadhesive having a melt flow temperature in the range between about 80°C. and about 200° C., or a molecularly flexible thermoplastic adhesivehaving a glass transition temperature of less than about 0° C., or amolecularly flexible thermoplastic adhesive having a melt flowtemperature in the range between about 80° C. and about 200° C. andhaving a glass transition temperature of less than about 0° C.; or amolecularly flexible thermoplastic adhesive having a melt flowtemperature in the range between about 80° C. and about 200° C. andhaving more than about ten percent (10%) molecular crystallites thatflow at melt flow temperatures in the range between about 80° C. andabout 200° C., or a molecularly flexible thermoplastic adhesive having aglass transition temperature of less than about 0° C. and having morethan about ten percent (10%) molecular crystallites that flow at meltflow temperatures in the range between about 80° C. and about 200° C.,or a molecularly flexible thermoplastic adhesive having a melt flowtemperature in the range between about 80° C. and about 200° C. andhaving a glass transition temperature of less than about 0° C. andhaving more than about ten percent (10%) molecular crystallites thatflow at melt flow temperatures in the range between about 80° C. andabout 200° C.; or any combination of the foregoing. The laminated module100, 200 including the top layer 200 and the rear sheet 300: may exhibita flexural modulus at about 60° C. that is at least fifty percent of theflexural modulus exhibited at about 20° C.; or may exhibit a flexuralmodulus at about 60° C. that is at least fifty percent of the flexuralmodulus exhibited at about 20° C. without cross-linking chemical curing;or may exhibit a flexural modulus at about 60° C. that is at least fiftypercent of the flexural modulus exhibited at about 20° C. and may havemore than about ten percent (10%) molecular crystallites that flow atmelt flow temperatures in a range between about 80° C. and about 200°C.; or may exhibit a flexural modulus at about 60° C. that is at leastfifty percent of the flexural modulus exhibited at about 20° C. withoutcross-linking chemical curing and may have more than about ten percent(10%) molecular crystallites that flow at melt flow temperatures in therange between about 80° C. and about 200° C.; or any combination of theforegoing. The top layer 200 may include: a polyvinylidene fluoride(PVDF), or a polyvinyl fluoride (PVF), or a copolymer thereof, or anethylene vinyl acetate (EVA), or a modified PVDF, or a fluorinatedpolymer, or a laminate of any or all of the foregoing; or the thermallyconductive rear sheet 300 may include: an EVA, or a PVF, or a PVDF,including thermally conductive particles so as to be thermallyconductive; or the top layer 200 may include: a PVDF, or a PVF, or acopolymer thereof, or an EVA, or a modified PVDF, or a fluorinatedpolymer, or a laminate of any or all of the foregoing; and the thermallyconductive rear sheet 300 may include: an EVA, or a PVF, or a PVDF,including thermally conductive particles so as to be thermallyconductive. The thermally conductive particles may include: alumina,zinc oxide, another thermally conductive electrically insulatingmaterial, or a combination thereof. The laminated module 100, 200 ofsolar cells 400 may further comprise: a glass layer on an exposed frontsurface of the optically transparent top layer 200; or a melt flowableoptically transparent fluorinated polymer front layer on an exposedfront surface of the optically transparent top layer 200; or a thermallyconductive layer on an exposed rear surface of the melt flowable rearsheet 300; or an ultraviolet resistant melt flowable layer on an exposedrear surface of the melt flowable rear sheet 300; or any combination ofthe foregoing. The top layer 200 may not be as thick as is the rearsheet 300; or the top layer 200 may be at least as thick as are thesolar cells 400; or the top layer 200 may not be as thick as is the rearsheet 300 and is at least as thick as are the solar cells 400. Theplurality of electrical connections 415, 525, 430 may comprise: a firstpattern of melt flowable electrically conductive thermoplastic adhesivebetween the top layer 200 and the front surfaces of the plurality ofsolar cells 400 and a second pattern of melt flowable electricallyconductive thermoplastic adhesive between the rear sheet 300 and theback surfaces of the plurality of solar cells 400, wherein the first andsecond patterns of melt flowable electrically conductive thermoplasticadhesive melt flow to each other to provide the electrical connections415, 525, 430 of the solar cells 400; or interconnection members 415,525, 430 may comprise solderable metal strips soldered to metalizedcontacts of the plurality of solar cells 400; or interconnection members415, 525, 430 may comprise metal strips each having on opposing broadsurfaces thereof a plurality of areas may comprise melt flowableelectrically conductive thermoplastic adhesive covering between aboutten percent and 100 percent of the area of the metal strip and meltflowable electrically insulating thermoplastic adhesive substantiallycovering the remaining area of the metal strip. The laminated module100, 200 of solar cells 400 may comprise a laminated solar cell panel.

A laminated module 100, 200 of solar cells 400 having front and backsurfaces may comprise: a plurality of solar cells 400 having front andback surfaces to which electrical connection is to be made; a top layer200 of an optically transparent electrically insulating materialadjacent to and having adhesion to the front surfaces of solar cells400, whereby light may pass through the optically transparent top layer200 to impinge upon the front surfaces of the plurality of solar cells400; a thermally conductive rear sheet 300 may comprise a thermallyconductive metal sheet and a melt flowed melt flowable thermallyconductive and electrically insulating thermoplastic adhesive materiallayer adjacent to and having adhesion to the back surfaces of solarcells 400, the thermally conductive rear sheet 300 having a thermalconductivity of at least 0.5 Watt per meter ° K; a plurality ofelectrical connections 415, 525, 430, each electrical connection beingbetween the front surface of one of the plurality of solar cells 400 andthe back surface of another of the plurality of solar cells 400, wherebyones of the plurality of solar cells 400 are electrically connected inseries; and the top layer 200, the thermally conductive rear sheet 300and the plurality of solar cells 400 being melt flow laminated with atleast the thermally conductive thermoplastic adhesive material layer ofthe rear sheet 300 melt flow laminating to the plurality of solar cells400; the top layer 200 adhering to the front surfaces of the pluralityof solar cells 400 and the melt flowed thermally conductive rear sheet300 adhering to the back surfaces of the plurality of solar cells 400;whereby heat from the plurality of solar cells 400 can be transferredvia the thermally conductive rear sheet 300. The thermally conductivemetal sheet may include a sheet of aluminum or copper or an alloythereof; or the thermally conductive metal sheet may have a thickness ofat least about 2 mils (0.002 inch); or the thermally conductive metalsheet may include a sheet of aluminum or copper or an alloy thereofhaving a thickness of at least about 2 mils (0.002 inch). The thermallyconductive metal sheet may comprise a honeycomb, a perforated laminate,a structural member, or a combination thereof. The melt flowablethermally conductive rear sheet 300 may have a thermal conductivity in arange of about 0.5-4.0 Watt per meter ° K; or the melt flowablethermally conductive rear sheet 300 may have a thermal conductivity ofup to about 20 Watt per meter ° K. The top layer 200, or the rear sheet300, or both, may comprise: a molecularly flexible thermoplasticadhesive having a melt flow temperature in the range between about 80°C. and about 200° C., or a molecularly flexible thermoplastic adhesivehaving a glass transition temperature of less than about 0° C., or amolecularly flexible thermoplastic adhesive having a melt flowtemperature in the range between about 80° C. and about 200° C. andhaving a glass transition temperature of less than about 0° C.; or amolecularly flexible thermoplastic adhesive having a melt flowtemperature in the range between about 80° C. and about 200° C. andhaving more than about ten percent (10%) molecular crystallites thatflow at melt flow temperatures in the range between about 80° C. andabout 200° C., or a molecularly flexible thermoplastic adhesive having aglass transition temperature of less than about 0° C. and having morethan about ten percent (10%) molecular crystallites that flow at meltflow temperatures in the range between about 80° C. and about 200° C.,or a molecularly flexible thermoplastic adhesive having a melt flowtemperature in the range between about 80° C. and about 200° C. andhaving a glass transition temperature of less than about 0° C. andhaving more than about ten percent (10%) molecular crystallites thatflow at melt flow temperatures in the range between about 80° C. andabout 200° C.; or any combination of the foregoing. The laminated module100, 200 of solar cells 400 including the top layer 200 and the rearsheet 300: may exhibit a flexural modulus at about 60° C. that is atleast fifty percent of the flexural modulus exhibited at about 20° C.;or may exhibit a flexural modulus at about 60° C. that is at least fiftypercent of the flexural modulus exhibited at about 20° C. withoutcross-linking chemical curing; or may exhibit a flexural modulus atabout 60° C. that is at least fifty percent of the flexural modulusexhibited at about 20° C. and may have more than about ten percent (10%)molecular crystallites that flow at melt flow temperatures in a rangebetween about 80° C. and about 200° C.; or may exhibit a flexuralmodulus at about 60° C. that is at least fifty percent of the flexuralmodulus exhibited at about 20° C. without cross-linking chemical curingand may have more than about ten percent (10%) molecular crystallitesthat flow at melt flow temperatures in the range between about 80° C.and about 200° C.; or any combination of the foregoing. The top layer200 may include: a polyvinylidene fluoride (PVDF), or a polyvinylfluoride (PVF), or a copolymer thereof, or an ethylene vinyl acetate(EVA), or a modified PVDF, or a fluorinated polymer, or a laminate ofany or all of the foregoing; or the thermally conductive rear sheet 300may include: an EVA, or a PVF, or a PVDF, including thermally conductiveparticles so as to be thermally conductive; or the top layer 200 mayinclude: a PVDF, or a PVF, or a copolymer thereof, or an EVA, or amodified PVDF, or a fluorinated polymer, or a laminate of any or all ofthe foregoing; and the thermally conductive rear sheet 300 may include:an EVA, or a PVF, or a PVDF, including thermally conductive particles soas to be thermally conductive. The thermally conductive particles mayinclude: alumina, zinc oxide, another thermally conductive electricallyinsulating material, or a combination thereof. The laminated module 100,200 of solar cells 400 may further comprise: a glass layer on an exposedfront surface of the optically transparent top layer 200; or a meltflowable optically transparent fluorinated polymer front layer on anexposed front surface of the optically transparent top layer 200; or athermally conductive layer on an exposed rear surface of the meltflowable rear sheet 300; or an ultraviolet resistant melt flowable layeron an exposed rear surface of the melt flowable rear sheet 300; or anycombination of the foregoing. The top layer 200 may not be as thick asis the rear sheet 300; or the top layer 200 may be at least as thick asare the solar cells 400; or the top layer 200 may be not as thick as isthe rear sheet 300 and at least as thick as are the solar cells 400. Theplurality of electrical connections 415, 525, 430 may comprise: a firstpattern of melt flowable electrically conductive thermoplastic adhesivebetween the top layer 200 and the front surfaces of the plurality ofsolar cells 400 and a second pattern of melt flowable electricallyconductive thermoplastic adhesive between the rear sheet 300 and theback surfaces of the plurality of solar cells 400, wherein the first andsecond patterns of melt flowable electrically conductive thermoplasticadhesive melt flow to each other to provide the electrical connections415, 525, 430 of the solar cells 400; or interconnection members 415,525, 430 may comprise solderable metal strips soldered to metalizedcontacts of the plurality of solar cells 400; or interconnection members415, 525, 430 may comprise metal strips each having on opposing broadsurfaces thereof a plurality of areas may comprise melt flowableelectrically conductive thermoplastic adhesive covering between aboutten percent and 100 percent of the area of the metal strip and meltflowable electrically insulating thermoplastic adhesive substantiallycovering the remaining area of the metal strip. The laminated module100, 200 of solar cells 400 may comprise a laminated solar cell panel100, 200.

As used herein, the term “about” means that dimensions, sizes,formulations, parameters, shapes and other quantities andcharacteristics are not and need not be exact, but may be approximateand/or larger or smaller, as desired, reflecting tolerances, conversionfactors, rounding off, measurement error and the like, and other factorsknown to those of skill in the art. In general, a dimension, size,formulation, parameter, shape or other quantity or characteristic is“about” or “approximate” whether or not expressly stated to be such. Itis noted that embodiments of very different sizes, shapes and dimensionsmay employ the described arrangements.

Although terms such as “up,” “down,” “left,” “right,” “front,” “rear,”“back,” side,” “top,” “bottom,” “forward,” “backward,” “under” and/or“over,” may be used herein as a convenience in describing one or moreembodiments and/or uses of the present arrangement, the articlesdescribed may be positioned in any desired orientation and/or may beutilized in any desired position and/or orientation, and even if such aterm might apply in use it may not apply in processing, manufactureand/or testing. Such terms of position and/or orientation should beunderstood as being for convenience only, and not as limiting of theinvention as claimed.

Further, what is stated as being “optimum” or “deemed optimum” may ornot be a true optimum condition, but is the condition deemed to bedesirable or acceptably “optimum” by virtue of its being selected inaccordance with the decision rules and/or criteria defined by theapplicable controlling function.

While the present invention has been described in terms of the foregoingexample embodiments, variations within the scope and spirit of thepresent invention as defined by the claims following will be apparent tothose skilled in the art. For example, the steps in any process, e.g.,that for forming top layer 200 and/or rear sheet 300, and/or formingother layers, may be performed in any desired suitable order.

For example, a top layer 200 may be formed by applying the electricallyconductive adhesive pattern 210, 220 and/or insulating pattern 250 to alayer or sheet 200 of suitable material, or the electrically conductivepattern 210, 220 and/or insulating adhesive pattern 250 may be formed ona release liner and top layer 200 may be applied thereto. In eithercase, the building up may be by applying wet adhesive, e.g., byscreening, stenciling, roll coating, masking, deposition, printing,screen printing, inkjet printing, and the like, or by laminating sheets,e.g., dried or B-staged sheets) of the various layers together using anyof the methods described or another suitable method. The same is truewhere one layer, e.g., top layer 200, has wells 202 or other raised orrecessed features that are conveniently formed by the building up ofplural layers, e.g., of layers with the features and layers withoutfeatures.

While melt flowable materials that melt flow at about the sametemperature are generally preferred, melt flowing at about the sametemperature should be understood to include a range of temperatures,e.g., an about 10-20° C. range of temperatures at or above a melt flowtemperature, as well as including melt flowing at about a particularmelt flow temperature, e.g., about 125° C. Preferably the melt flowtemperatures of all of the melt flowable materials employed in a givensolar cell panel 100 should be above the highest temperature at whichthe solar cell panel 100 is expected to be used or is rated or specifiedto be used. Preferably, the melt flow temperature of the electricallyconductive thermoplastic adhesives should be in the range between about80° C. and about 200° C., and may have a slightly lower melt flowtemperature, e.g., about 10-20° C. lower, than does the substrate onwhich they are applied.

In a further alternative, process 580 may in effect combine steps584-586 by applying a solvent, e.g., NMP or MEK, to a substrate layer orsheet, e.g., a FP or NFP sheet or layer, then laminating that substratesheet to the obtained 582 substrate layer or sheet, e.g., at ambienttemperature or at a slightly elevated temperature, e.g., at about25-100° C., and then slowly drying 588 the laminate to drive the solventout of the interface between the sheets so as to not create voids orbubbles, either in the layers or sheets or at their interface. Adhesionmay also be promoted by employing a blend of polymers, e.g., by blendingPVF and/or PVDF and/or their co-polymers with a non-fluorinated polymer,e.g., about 5-75% of EVA or an acrylic and the like, as may be desiredfor improving adhesion to glass and/or solar cells.

Conventional melt film extension may also be employed to producefluorinated polymer films for top sheet 200 so long as the fluorinatedpolymer resins are pre-blended or pre-mixed to resins suitable forforming a film.

Although rolling heat laminating is the preferred laminating method,solar cell interconnections, module 100, 200 s and solar cell panelsaccording to the present arrangement may be made utilizing heatedpressing lamination and/or heated vacuum lamination.

While simple metals may be described, e.g., copper, aluminum, and tin,metals should be understood to include the metals and/or their alloys,e.g., brass, beryllium copper, and the like, as well as metals having aflash, plated or other coating, e.g., tin, nickel, silver, nickel-tin,nickel-silver, copper-nickel, copper-nickel-silver, and combinationsthereof that resist oxidation which can increase the contact resistanceof the base layer or metal. Likewise, solder should be understood toinclude a solder of any type, whether tin based, silver based, leadbased or based on another metal. For electrically conductive adhesivetabbing, a metal finish such as a tin, nickel, silver, nickel-silver orother oxidation resistant finish is preferred.

Each of the U.S. Provisional Applications, U.S. Patent Applications,and/or U.S. Patents identified herein are hereby incorporated herein byreference in their entirety, for any purpose and for all purposesirrespective of how it may be referred to herein.

Finally, numerical values stated are typical or example values, are notlimiting values, and do not preclude substantially larger and/orsubstantially smaller values. Values in any given embodiment may besubstantially larger and/or may be substantially smaller than theexample or typical values stated.

What is claimed is:
 1. A laminated module of solar cells having frontand back surfaces comprising: a plurality of solar cells having frontand back surfaces to which electrical connection is to be made; a toplayer of an optically transparent electrically insulating materialadjacent to and having adhesion to the front surfaces of solar cells,whereby light may pass through said optically transparent top layer toimpinge upon the front surfaces of said plurality of solar cells; athermally conductive rear sheet including a melt flowed melt flowablethermally conductive and electrically insulating thermoplastic adhesivematerial adjacent to and having adhesion to the back surfaces of solarcells; a plurality of electrical connections, each electrical connectionbeing between the front surface of one of said plurality of solar cellsand the back surface of another of said plurality of solar cells,whereby ones of said plurality of solar cells are electrically connectedin series; and said top layer, said thermally conductive rear sheet andsaid plurality of solar cells being melt flow laminated with at leastthe melt flowed thermally conductive thermoplastic adhesive material ofsaid thermally conductive rear sheet melt flow laminating to saidplurality of solar cells; said top layer adhering to the front surfacesof said plurality of solar cells and said thermally conductive rearsheet adhering to the back surfaces of said plurality of solar cells,whereby heat from said plurality of solar cells can be transferred viasaid thermally conductive rear sheet.
 2. The laminated module of solarcells of claim 1 further comprising: a thermally conductive metal sheetthermally coupled to an exposed rear surface of said melt flowable rearsheet.
 3. The laminated module of solar cells of claim 2 wherein: thethermally conductive metal sheet includes a sheet of aluminum or copperor an alloy thereof; or the thermally conductive metal sheet has athickness of at least about 2 mils (0.002 inch); or the thermallyconductive metal sheet includes a sheet of aluminum or copper or analloy thereof having a thickness of at least about 2 mils (0.002 inch).4. The laminated module of solar cells of claim 2 wherein the thermallyconductive metal sheet comprises a honeycomb, a perforated laminate, astructural member, or a combination thereof.
 5. The laminated module ofsolar cells of claim 1 wherein: said melt flowable thermally conductiverear sheet has a thermal conductivity in a range of about 0.5-4.0 Wattper meter ° K; or said melt flowable thermally conductive rear sheet hasa thermal conductivity of up to about 20 Watt per meter ° K.
 6. Thelaminated module of solar cells of claim 1 wherein said top layer, orsaid rear sheet, or both, comprise: a molecularly flexible thermoplasticadhesive having a melt flow temperature in the range between about 80°C. and about 200° C., or a molecularly flexible thermoplastic adhesivehaving a glass transition temperature of less than about 0° C., or amolecularly flexible thermoplastic adhesive having a melt flowtemperature in the range between about 80° C. and about 200° C. andhaving a glass transition temperature of less than about 0° C.; or amolecularly flexible thermoplastic adhesive having a melt flowtemperature in the range between about 80° C. and about 200° C. andhaving more than about ten percent (10%) molecular crystallites thatflow at melt flow temperatures in the range between about 80° C. andabout 200° C., or a molecularly flexible thermoplastic adhesive having aglass transition temperature of less than about 0° C. and having morethan about ten percent (10%) molecular crystallites that flow at meltflow temperatures in the range between about 80° C. and about 200° C.,or a molecularly flexible thermoplastic adhesive having a melt flowtemperature in the range between about 80° C. and about 200° C. andhaving a glass transition temperature of less than about 0° C. andhaving more than about ten percent (10%) molecular crystallites thatflow at melt flow temperatures in the range between about 80° C. andabout 200° C.; or any combination of the foregoing.
 7. The laminatedmodule of solar cells of claim 1 wherein the laminated module includingthe top layer and the rear sheet: exhibits a flexural modulus at about60° C. that is at least fifty percent of the flexural modulus exhibitedat about 20° C.; or exhibits a flexural modulus at about 60° C. that isat least fifty percent of the flexural modulus exhibited at about 20° C.without cross-linking chemical curing; or exhibits a flexural modulus atabout 60° C. that is at least fifty percent of the flexural modulusexhibited at about 20° C. and has more than about ten percent (10%)molecular crystallites that flow at melt flow temperatures in a rangebetween about 80° C. and about 200° C.; or exhibits a flexural modulusat about 60° C. that is at least fifty percent of the flexural modulusexhibited at about 20° C. without cross-linking chemical curing and hasmore than about ten percent (10%) molecular crystallites that flow atmelt flow temperatures in the range between about 80° C. and about 200°C.; or any combination of the foregoing.
 8. The laminated module ofsolar cells of claim 1 wherein: said top layer includes: apolyvinylidene fluoride (PVDF), or a polyvinyl fluoride (PVF), or acopolymer thereof, or an ethylene vinyl acetate (EVA), or a modifiedPVDF, or a fluorinated polymer, or a laminate of any or all of theforegoing; or said thermally conductive rear sheet includes: an EVA, ora PVF, or a PVDF, including thermally conductive particles so as to bethermally conductive; or said top layer includes: a PVDF, or a PVF, or acopolymer thereof, or an EVA, or a modified PVDF, or a fluorinatedpolymer, or a laminate of any or all of the foregoing; and saidthermally conductive rear sheet includes: an EVA, or a PVF, or a PVDF,including thermally conductive particles so as to be thermallyconductive.
 9. The laminated module of solar cells of claim 8 wherein:the thermally conductive particles include: alumina, zinc oxide, anotherthermally conductive electrically insulating material, or a combinationthereof.
 10. The laminated module of solar cells of claim 1 furthercomprising: a glass layer on an exposed front surface of said opticallytransparent top layer; or a melt flowable optically transparentfluorinated polymer front layer on an exposed front surface of saidoptically transparent top layer; or a thermally conductive layer on anexposed rear surface of said melt flowable rear sheet; or an ultravioletresistant melt flowable layer on an exposed rear surface of said meltflowable rear sheet; or any combination of the foregoing.
 11. Thelaminated module of solar cells of claim 1 wherein: said top layer isnot as thick as is said rear sheet; or said top layer is at least asthick as are said solar cells; or said top layer is not as thick as issaid rear sheet and is at least as thick as are said solar cells. 12.The laminated module of solar cells of claim 1 wherein said plurality ofelectrical connections comprise: a first pattern of melt flowableelectrically conductive thermoplastic adhesive between said top layerand the front surfaces of said plurality of solar cells and a secondpattern of melt flowable electrically conductive thermoplastic adhesivebetween said rear sheet and the back surfaces of said plurality of solarcells, wherein said first and second patterns of melt flowableelectrically conductive thermoplastic adhesive melt flow to each otherto provide the electrical connections of the solar cells; orinterconnection members comprising solderable metal strips soldered tometalized contacts of said plurality of solar cells; or interconnectionmembers comprising metal strips each having on opposing broad surfacesthereof a plurality of areas comprising melt flowable electricallyconductive thermoplastic adhesive covering between about ten percent and100 percent of the area of said metal strip and melt flowableelectrically insulating thermoplastic adhesive substantially coveringthe remaining area of said metal strip.
 13. The laminated module ofsolar cells of claim 1 wherein said laminated module of solar cellscomprises a laminated solar cell panel.
 14. A laminated module of solarcells having front and back surfaces comprising: a plurality of solarcells having front and back surfaces to which electrical connection isto be made; a top layer of an optically transparent electricallyinsulating material adjacent to and having adhesion to the frontsurfaces of solar cells, whereby light may pass through said opticallytransparent top layer to impinge upon the front surfaces of saidplurality of solar cells; a thermally conductive rear sheet comprising athermally conductive metal sheet and a melt flowed melt flowablethermally conductive and electrically insulating thermoplastic adhesivematerial layer adjacent to and having adhesion to the back surfaces ofsolar cells, said thermally conductive rear sheet having a thermalconductivity of at least 0.5 Watt per meter ° K; a plurality ofelectrical connections, each electrical connection being between thefront surface of one of said plurality of solar cells and the backsurface of another of said plurality of solar cells, whereby ones ofsaid plurality of solar cells are electrically connected in series; andsaid top layer, said thermally conductive rear sheet and said pluralityof solar cells being melt flow laminated with at least the thermallyconductive thermoplastic adhesive material layer of said rear sheet meltflow laminating to said plurality of solar cells; said top layeradhering to the front surfaces of said plurality of solar cells and saidmelt flowed thermally conductive rear sheet adhering to the backsurfaces of said plurality of solar cells; whereby heat from saidplurality of solar cells can be transferred via said thermallyconductive rear sheet.
 15. The laminated module of solar cells of claim14 wherein: the thermally conductive metal sheet includes a sheet ofaluminum or copper or an alloy thereof; or the thermally conductivemetal sheet has a thickness of at least about 2 mils (0.002 inch); orthe thermally conductive metal sheet includes a sheet of aluminum orcopper or an alloy thereof having a thickness of at least about 2 mils(0.002 inch).
 16. The laminated module of solar cells of claim 15wherein the thermally conductive metal sheet comprises a honeycomb, aperforated laminate, a structural member, or a combination thereof. 17.The laminated module of solar cells of claim 14 wherein: said meltflowable thermally conductive rear sheet has a thermal conductivity in arange of about 0.5-4.0 Watt per meter ° K; or said melt flowablethermally conductive rear sheet has a thermal conductivity of up toabout 20 Watt per meter ° K.
 18. The laminated module of solar cells ofclaim 14 wherein said top layer, or said rear sheet, or both, comprise:a molecularly flexible thermoplastic adhesive having a melt flowtemperature in the range between about 80° C. and about 200° C., or amolecularly flexible thermoplastic adhesive having a glass transitiontemperature of less than about 0° C., or a molecularly flexiblethermoplastic adhesive having a melt flow temperature in the rangebetween about 80° C. and about 200° C. and having a glass transitiontemperature of less than about 0° C.; or a molecularly flexiblethermoplastic adhesive having a melt flow temperature in the rangebetween about 80° C. and about 200° C. and having more than about tenpercent (10%) molecular crystallites that flow at melt flow temperaturesin the range between about 80° C. and about 200° C., or a molecularlyflexible thermoplastic adhesive having a glass transition temperature ofless than about 0° C. and having more than about ten percent (10%)molecular crystallites that flow at melt flow temperatures in the rangebetween about 80° C. and about 200° C., or a molecularly flexiblethermoplastic adhesive having a melt flow temperature in the rangebetween about 80° C. and about 200° C. and having a glass transitiontemperature of less than about 0° C. and having more than about tenpercent (10%) molecular crystallites that flow at melt flow temperaturesin the range between about 80° C. and about 200° C.; or any combinationof the foregoing.
 19. The laminated module of solar cells of claim 14wherein the laminated module including the top layer and the rear sheet:exhibits a flexural modulus at about 60° C. that is at least fiftypercent of the flexural modulus exhibited at about 20° C.; or exhibits aflexural modulus at about 60° C. that is at least fifty percent of theflexural modulus exhibited at about 20° C. without cross-linkingchemical curing; or exhibits a flexural modulus at about 60° C. that isat least fifty percent of the flexural modulus exhibited at about 20° C.and has more than about ten percent (10%) molecular crystallites thatflow at melt flow temperatures in a range between about 80° C. and about200° C.; or exhibits a flexural modulus at about 60° C. that is at leastfifty percent of the flexural modulus exhibited at about 20° C. withoutcross-linking chemical curing and has more than about ten percent (10%)molecular crystallites that flow at melt flow temperatures in the rangebetween about 80° C. and about 200° C.; or any combination of theforegoing.
 20. The laminated module of solar cells of claim 14 wherein:said top layer includes: a polyvinylidene fluoride (PVDF), or apolyvinyl fluoride (PVF), or a copolymer thereof, or an ethylene vinylacetate (EVA), or a modified PVDF, or a fluorinated polymer, or alaminate of any or all of the foregoing; or said thermally conductiverear sheet includes: an EVA, or a PVF, or a PVDF, including thermallyconductive particles so as to be thermally conductive; or said top layerincludes: a PVDF, or a PVF, or a copolymer thereof, or an EVA, or amodified PVDF, or a fluorinated polymer, or a laminate of any or all ofthe foregoing; and said thermally conductive rear sheet includes: anEVA, or a PVF, or a PVDF, including thermally conductive particles so asto be thermally conductive.
 21. The laminated module of solar cells ofclaim 20 wherein: the thermally conductive particles include: alumina,zinc oxide, another thermally conductive electrically insulatingmaterial, or a combination thereof.
 22. The laminated module of solarcells of claim 14 further comprising: a glass layer on an exposed frontsurface of said optically transparent top layer; or a melt flowableoptically transparent fluorinated polymer front layer on an exposedfront surface of said optically transparent top layer; or a thermallyconductive layer on an exposed rear surface of said melt flowable rearsheet; or an ultraviolet resistant melt flowable layer on an exposedrear surface of said melt flowable rear sheet; or any combination of theforegoing.
 23. The laminated module of solar cells of claim 14 wherein:said top layer is not as thick as is said rear sheet; or said top layeris at least as thick as are said solar cells; or said top layer is notas thick as is said rear sheet and is at least as thick as are saidsolar cells.
 24. The laminated module of solar cells of claim 14 whereinsaid plurality of electrical connections comprise: a first pattern ofmelt flowable electrically conductive thermoplastic adhesive betweensaid top layer and the front surfaces of said plurality of solar cellsand a second pattern of melt flowable electrically conductivethermoplastic adhesive between said rear sheet and the back surfaces ofsaid plurality of solar cells, wherein said first and second patterns ofmelt flowable electrically conductive thermoplastic adhesive melt flowto each other to provide the electrical connections of the solar cells;or interconnection members comprising solderable metal strips solderedto metalized contacts of said plurality of solar cells; orinterconnection members comprising metal strips each having on opposingbroad surfaces thereof a plurality of areas comprising melt flowableelectrically conductive thermoplastic adhesive covering between aboutten percent and 100 percent of the area of said metal strip and meltflowable electrically insulating thermoplastic adhesive substantiallycovering the remaining area of said metal strip.
 25. The laminatedmodule of solar cells of claim 14 wherein said laminated module of solarcells comprises a laminated solar cell panel.